
ICSE Class 10 Maths Selina Solutions Chapter 24 is an essential resource for students preparing for the Mathematics exam on 2 March 2026, especially as the ICSE Class 10 board exams have started from 17 February 2026. This chapter provides detailed step-by-step solutions, worked examples, and a variety of practice problems to help students understand key concepts clearly.
By revising Chapter 24 thoroughly, students can strengthen their problem-solving skills, learn how to apply formulas accurately, and tackle both simple and complex questions with confidence. The solutions are explained in a simple and easy-to-follow language, making last-minute revision effective and helping students maximise their marks in the board exam.
Regular practice with these solutions also helps students identify recurring question patterns, improve speed and accuracy, and build the confidence needed to perform well under exam conditions.
1. Find the mean of the following set of numbers:
(i) 6, 9, 11, 12 and 7
(ii) 11, 14, 23, 26, 10, 12, 18 and 6
Solution:
(i) By definition, we know Mean = ∑x/ n Here, n = 5 Thus, Mean = (6 + 9 + 11 + 12 + 7)/ 5 = 45/5 = 9 (ii) By definition, we know Mean = ∑x/ n Here, n = 8 Thus, Mean = (11 + 14 + 23 + 26 + 10 + 12 + 18 + 6)/ 8 = 120/8 = 152. Marks obtained (in mathematics) by 9 student are given below:
60, 67, 52, 76, 50, 51, 74, 45 and 56
(a) find the arithmetic mean
(b) if marks of each student be increased by 4; what will be the new value of arithmetic mean.
Solution:
(a) Mean = ∑x/ n Here, n = 9 Thus, Mean = (60 + 67 + 52 + 76 + 50 + 51 + 74 + 45 + 56)/ 9 = 531/9 = 59 (b) If the marks of each student be increased by 4 then new arithmetic mean will be = 59 + 4 = 633. Find the mean of the natural numbers from 3 to 12.
Solution:
The numbers between 3 to 12 are 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12. Here n = 10 Mean = ∑x/ n = (3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12)/ 10 = 75/10 = 7.54. (a) Find the mean of 7, 11, 6, 5, and 6
(b) If each number given in (a) is diminished by 2, find the new value of mean.
Solution:
(a) Mean = ∑x/ n , here n = 5 = (7 + 11 + 6 + 5 + 6)/ 5 = 35/5 = 7 (b) If 2 is subtracted from each number, then the mean will he changed as 7 – 2 = 55. If the mean of 6, 4, 7, ‘a’ and 10 is 8. Find the value of ‘a’
Solution:
Given, No. of terms (n) = 5 Mean = 8 Sum of all terms = 8 x 5 = 40 …… (i) But, sum of numbers = 6 + 4 + 7 + a + 10 = 27 + a ….. (ii) On equating (i) and (ii), we get 27 + a = 40 Thus, a = 136. The mean of the number 6, ‘y’, 7, ‘x’ and 14 is 8. Express ‘y’ in terms of ‘x’.
Solution:
Given, No. of terms (n) = 5 and mean = 8 So, the sum of all terms = 5 x 8 = 40 ……. (i) but sum of numbers = 6 + y + 7 + x + 14 = 27 + y + x ……. (ii) On equating (i) and (ii), we get 27 + y + x = 40 x + y = 13 Hence, y = 13 – x7. The ages of 40 students are given in the following table:
| Age( in yrs) | 12 | 13 | 14 | 15 | 16 | 17 | 18 |
| Frequency | 2 | 4 | 6 | 9 | 8 | 7 | 4 |
Find the arithmetic mean.
Solution:
| Age in yrs x i | Frequency (f i ) | f i x i |
| 12 | 2 | 24 |
| 13 | 4 | 52 |
| 14 | 6 | 84 |
| 15 | 9 | 135 |
| 16 | 8 | 128 |
| 17 | 7 | 119 |
| 18 | 4 | 72 |
| Total | 40 | 614 |
1. The following table gives the ages of 50 students of a class. Find the arithmetic mean of their ages.
| Age – Years | 16 – 18 | 18 – 20 | 20 – 22 | 22- 24 | 24-26 |
| No. of Students | 2 | 7 | 21 | 17 | 3 |
Solution:
| Age in years C.I. | x i | Number of students (f i ) | x i f i |
| 16 – 18 | 17 | 2 | 34 |
| 18 – 20 | 19 | 7 | 133 |
| 20 – 22 | 21 | 21 | 441 |
| 22 – 24 | 23 | 17 | 391 |
| 24 – 26 | 25 | 3 | 75 |
| Total | 50 | 1074 |
2. The following table gives the weekly wages of workers in a factory.
| Weekly Wages (Rs) | No. of Workers |
| 50-55 | 5 |
| 55-60 | 20 |
| 60-65 | 10 |
| 65-70 | 10 |
| 70-75 | 9 |
| 75-80 | 6 |
| 80-85 | 12 |
| 85-90 | 8 |
Calculate the mean by using:
(i) Direct Method
(ii) Short – Cut Method
Solution:
(i) Direct Method| Weekly Wages (Rs) | Mid-Value x i | No. of Workers (f i ) | f i x i |
| 50-55 | 52.5 | 5 | 262.5 |
| 55-60 | 57.5 | 20 | 1150.0 |
| 60-65 | 62.5 | 10 | 625.0 |
| 65-70 | 67.5 | 10 | 675.0 |
| 70-75 | 72.5 | 9 | 652.5 |
| 75-80 | 77.5 | 6 | 465.0 |
| 80-85 | 82.5 | 12 | 990.0 |
| 85-90 | 87.5 | 8 | 700.0 |
| Total | 80 | 5520.00 |
| Weekly wages (Rs) | No. of workers (f i ) | Mid-value x i | A = 72.5 d i = x – A | f i d i |
| 50-55 | 5 | 52.5 | -20 | -100 |
| 55-60 | 20 | 57.5 | -15 | -300 |
| 60-65 | 10 | 62.5 | -10 | -100 |
| 65-70 | 10 | 67.5 | -5 | -50 |
| 70-75 | 9 | A = 72.5 | 0 | 0 |
| 75-80 | 6 | 77.5 | 5 | 30 |
| 80-85 | 12 | 82.5 | 10 | 120 |
| 85-90 | 8 | 87.5 | 15 | 120 |
| Total | 80 | -280 |
3. The following are the marks obtained by 70 boys in a class test:
| Marks | No. of boys |
| 30 – 40 | 10 |
| 40 – 50 | 12 |
| 50 – 60 | 14 |
| 60 – 70 | 12 |
| 70 – 80 | 9 |
| 80 – 90 | 7 |
| 90 – 100 | 6 |
Calculate the mean by:
(i) Short – cut method
(ii) Step – deviation method
Solution:
(i) Short – cut method| Marks | No. of boys (f i ) | Mid-value x i | A = 65 d i = x – A | f i d i |
| 30 – 40 | 10 | 35 | -30 | -300 |
| 40 – 50 | 12 | 45 | -20 | -240 |
| 50 – 60 | 14 | 55 | -10 | -140 |
| 60 – 70 | 12 | A = 65 | 0 | 0 |
| 70 – 80 | 9 | 75 | 10 | 90 |
| 80 – 90 | 7 | 85 | 20 | 140 |
| 90 – 100 | 6 | 95 | 30 | 180 |
| Total | 70 | -270 |
(ii) Step – deviation method
| Marks | No. of boys (f i ) | Mid-value x i | A = 65 u i = (x i – A)/ h | f i u i |
| 30 – 40 | 10 | 35 | -3 | -30 |
| 40 – 50 | 12 | 45 | -2 | -24 |
| 50 – 60 | 14 | 55 | -1 | -14 |
| 60 – 70 | 12 | A = 65 | 0 | 0 |
| 70 – 80 | 9 | 75 | 1 | 9 |
| 80 – 90 | 7 | 85 | 2 | 14 |
| 90 – 100 | 6 | 95 | 3 | 18 |
| Total | 70 | -27 |
4. Find mean by step – deviation method:
| C. I. | 63-70 | 70-77 | 77-84 | 84-91 | 91-98 | 98-105 | 105-112 |
| Freq | 9 | 13 | 27 | 38 | 32 | 16 | 15 |
Solution:
| C. I. | Frequency (f i ) | Mid-value x i | A = 87.50 u i = (x i – A)/ h | f i u i |
| 63 – 70 | 9 | 66.50 | -3 | -27 |
| 70 – 77 | 13 | 73.50 | -2 | -26 |
| 77 – 84 | 27 | 80.50 | -1 | -27 |
| 84 – 91 | 38 | A = 87.50 | 0 | 0 |
| 91 – 98 | 32 | 94.50 | 1 | 32 |
| 98 – 105 | 16 | 101.50 | 2 | 32 |
| 105 – 112 | 15 | 108.50 | 3 | 45 |
| Total | 150 | 29 |
5. The mean of the following frequency distribution is
. Find the value of ‘f’.
| C. I. | 0 – 10 | 10 – 20 | 20 – 30 | 30 – 40 | 40 – 50 |
| freq | 8 | 22 | 31 | f | 2 |
Solution:
Given,
| C. I. | frequency | Mid-value (x i ) | f i x i |
| 0-10 | 8 | 5 | 40 |
| 10-20 | 22 | 15 | 330 |
| 20-30 | 31 | 25 | 775 |
| 30-40 | f | 35 | 35f |
| 40-50 | 2 | 45 | 90 |
| Total | 63 + f | 1235 + 35f |
9324 + 148f = 8645 + 245f 245f – 148f = 9324 – 8645 f = 679/97 Thus, f = 7
1. A student got the following marks in 9 questions of a question paper.
3, 5, 7, 3, 8, 0, 1, 4 and 6.
Find the median of these marks.
Solution:
Arranging the given data in descending order: 8, 7, 6, 5, 4, 3, 3, 1, 0 Clearly, the middle term is 4 which is the 5 th term. Hence, median = 42. The weights (in kg) of 10 students of a class are given below:
21, 28.5, 20.5, 24, 25.5, 22, 27.5, 28, 21 and 24.
Find the median of their weights.
Solution:
Arranging the given data in descending order: 28.5, 28, 27.5, 25.5, 24, 24, 22, 21, 21, 20.5 It’s seen that, The middle terms are 24 and 24, 5 th and 6 th terms Thus, Median = (24 + 24)/ 2 = 48/2 = 243. The marks obtained by 19 students of a class are given below:
27, 36, 22, 31, 25, 26, 33, 24, 37, 32, 29, 28, 36, 35, 27, 26, 32, 35 and 28. Find:
(i) median (ii) lower quartile
(iii) upper quartile (iv) interquartile range
Solution:
Arranging in ascending order: 22, 24, 25, 26, 26, 27, 27, 28, 28, 29, 21, 32, 32, 33, 35, 35, 36, 36, 37 (i) The middle term is 10 th term i.e. 29 Hence, median = 29 (ii) Lower quartile
(iii) Upper quartile =
(iv) Interquartile range = q 3 – q 1 =35 – 26 = 9
4. From the following data, find:
(i) Median
(ii) Upper quartile
(iii) Inter-quartile range
25, 10, 40, 88, 45, 60, 77, 36, 18, 95, 56, 65, 7, 0, 38 and 83
Solution:
Arranging the given data in ascending order, we have: 0, 7, 10, 18, 25, 36, 38, 40, 45, 56, 60, 65, 77, 83, 88, 95 (i) Median is the mean of 8 th and 9 th term Thus, median = (40 + 45)/ 2 = 85/2 = 42.5 (ii) Upper quartile =
(iii) Interquartile range is given by, q 1 = 16 th /4 term = 18; q 3 = 65 Interquartile range = q 3 – q 1 Thus, q 3 – q 1 = 65 – 18 = 47
5. The ages of 37 students in a class are given in the following table:
| Age (in years) | 11 | 12 | 13 | 14 | 15 | 16 |
| Frequency | 2 | 4 | 6 | 10 | 8 | 7 |
Find the median.
Solution:
| Age (in years) | Frequency | Cumulative Frequency |
| 11 | 2 | 2 |
| 12 | 4 | 6 |
| 13 | 6 | 12 |
| 14 | 10 | 22 |
| 15 | 8 | 30 |
| 16 | 7 | 37 |
And, the 19 th term is 14 Therefore, the median = 14
1. Find the mode of the following data:
(i) 7, 9, 8, 7, 7, 6, 8, 10, 7 and 6
(ii) 9, 11, 8, 11, 16, 9, 11, 5, 3, 11, 17 and 8
Solution:
(i) It’s seen that 7 occurs 4 times in the given data. Hence, mode = 7 (ii) Mode = 11 As 11 occurs 4 times in the given data.2. The following table shows the frequency distribution of heights of 50 boys:
| Height (cm) | 120 | 121 | 122 | 123 | 124 |
| Frequency | 5 | 8 | 18 | 10 | 9 |
Find the mode of heights.
Solution:
Clearly, Mode is 122 cm because it has occurred the maximum number of times. i.e. frequency is 18.3. Find the mode of following data, using a histogram:
| Class | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 |
| Frequency | 5 | 12 | 20 | 9 | 4 |
Solution:
Clearly, Mode is in 20-30, because in this class there are 20 frequencies.
4. The following table shows the expenditure of 60 boys on books. Find the mode of their expenditure:
| Expenditure
(Rs) |
No. of
students |
| 20-25 | 4 |
| 25-30 | 7 |
| 30-35 | 23 |
| 35-40 | 18 |
| 40-45 | 6 |
| 45-50 | 2 |
Solution:
Clearly, Mode is in 30-35 because it has the maximum frequency.
1. The following distribution represents the height of 160 students of a school.
| Height (in cm) | No. of Students |
| 140 – 145 | 12 |
| 145 – 150 | 20 |
| 150 – 155 | 30 |
| 155 – 160 | 38 |
| 160 – 165 | 24 |
| 165 – 170 | 16 |
| 170 – 175 | 12 |
| 175 – 180 | 8 |
Draw an ogive for the given distribution taking 2 cm = 5 cm of height on one axis and 2 cm = 20 students on the other axis. Using the graph, determine:
i. The median height.
ii. The interquartile range.
iii. The number of students whose height is above 172 cm.
Solution:
| Height (in cm) | No. of Students | Cumulative frequency |
| 140 – 145 | 12 | 12 |
| 145 – 150 | 20 | 32 |
| 150 – 155 | 30 | 62 |
| 155 – 160 | 38 | 100 |
| 160 – 165 | 24 | 124 |
| 165 – 170 | 16 | 140 |
| 170 – 175 | 12 | 152 |
| 175 – 180 | 8 | 160 |
| N = 160 |
(i) So, Median = 160/2 = 80 th term Through mark for 80, draw a parallel line to x-axis which meets the curve; then from the curve draw a vertical line which meets the x-axis at the mark of 157.5. (ii) As, the number of terms = 160 Lower quartile (Q 1 ) = (160/4) = 40 th term = 152 Upper quartile (Q 3 ) = (3 x 160/4) = 120 th term = 164 Inner Quartile range = Q 3 – Q 1 = 164 – 152 = 12 (iii) Through mark for 172 on x-axis, draw a vertical line which meets the curve; then from the curve draw a horizontal line which meets the y-axis at the mark of 145. Now, The number of students whose height is above 172 cm = 160 – 144 = 16
2. Draw ogive for the data given below and from the graph determine: (i) the median marks.
(ii) the number of students who obtained more than 75% marks.
| Marks | 10 – 19 | 20 -29 | 30 – 39 | 40 – 49 | 50 – 59 | 60 – 69 | 70 – 79 | 80 – 89 | 90 – 99 |
| No. of students | 14 | 16 | 22 | 26 | 18 | 11 | 6 | 4 | 3 |
Solution:
| Marks | No. of students | Cumulative frequency |
| 9.5 – 19.5 | 14 | 14 |
| 19.5 – 29.5 | 16 | 30 |
| 29.5 – 39.5 | 22 | 52 |
| 39.5 – 49.5 | 26 | 78 |
| 49.5 – 59.5 | 18 | 96 |
| 59.5 – 69.5 | 11 | 107 |
| 69.5 – 79.5 | 6 | 113 |
| 79.5 – 89.5 | 4 | 117 |
| 89.5 – 99.5 | 3 | 120 |
(i) So, the median = 120/ 2 = 60 th term Through mark 60, draw a parallel line to x-axis which meets the curve at A. From A, draw a perpendicular to x-axis meeting it at B. The value of point B is the median = 43 (ii) Total marks = 100 75% of total marks = 75/100 x 100 = 75 marks Hence, the number of students getting more than 75% marks = 120 – 111 = 9 students.
3. The mean of 1, 7, 5, 3, 4 and 4 is m. The numbers 3, 2, 4, 2, 3, 3 and p have mean m – 1 and median q. Find p and q.
Solution:
Mean of 1, 7, 5, 3, 4 and 4 = (1 + 7 + 5 + 3 + 4 + 4)/ 6 = 24/6 = 4 So, m = 4 Now, given that The mean of 3, 2, 4, 2, 3, 3 and p = m -1 = 4 – 1 = 3 Thus, 17 + p = 3 x n …. ,where n = 7 17 + p = 21 p = 4 Arranging the terms in ascending order, we have: 2, 2, 3, 3, 3, 3, 4, 4 Mean = 4 th term = 3 Hence, q = 34. In a malaria epidemic, the number of cases diagnosed were as follows:
| Date (July) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| Number | 5 | 12 | 20 | 27 | 46 | 30 | 31 | 18 | 11 | 5 | 0 | 1 |
On what days do the mode and upper and lower quartiles occur?
Solution:
| Date | Number | C.f. |
| 1 | 5 | 5 |
| 2 | 12 | 17 |
| 3 | 20 | 37 |
| 4 | 27 | 64 |
| 5 | 46 | 110 |
| 6 | 30 | 140 |
| 7 | 31 | 171 |
| 8 | 18 | 189 |
| 9 | 11 | 200 |
| 10 | 5 | 205 |
| 11 | 0 | 205 |
| 12 | 1 | 206 |
5. The income of the parents of 100 students in a class in a certain university are tabulated below.
| Income (in thousand Rs) | 0 – 8 | 8 – 16 | 16 – 24 | 24 – 32 | 32 – 40 |
| No. of students | 8 | 35 | 35 | 14 | 8 |
(i) Draw a cumulative frequency curve to estimate the median income.
(ii) If 15% of the students are given freeships on the basis of the basis of the income of their parents, find the annual income of parents, below which the freeships will be awarded.
(iii) Calculate the Arithmetic mean.
Solution:
(i) Cumulative Frequency Curve
| Income (in thousand Rs.) | No. of students f | Cumulative Frequency | Class mark x | fx |
| 0 – 8 | 8 | 8 | 4 | 32 |
| 8 – 16 | 35 | 43 | 12 | 420 |
| 16 – 24 | 35 | 78 | 20 | 700 |
| 24 – 32 | 14 | 92 | 28 | 392 |
| 32 – 40 | 8 | 100 | 36 | 288 |
| ∑f = 100 | ∑ fx = 1832 |
6. The marks of 20 students in a test were as follows:
2, 6, 8, 9, 10, 11, 11, 12, 13, 13, 14, 14, 15, 15, 15, 16, 16, 18, 19 and 20.
Calculate:
(i) the mean (ii) the median (iii) the mode
Solution:
Arranging the terms in ascending order: 2, 6, 8, 9, 10, 11, 11, 12, 13, 13, 14, 14, 15, 15, 15, 16, 16, 18, 19, 20 Number of terms = 20 ∑ x = 2 + 6 + 8 + 9 + 11 + 11 + 12 + 13 + 13 + 14 + 14 + 15 + 15 + 15 + 15 + 16 + 16 + 18 + 19 + 20 = 257 (i) Mean = ∑x/ ∑n = 257/ 20 = 12.85 (ii) Median = (10 th term + 11 th term)/ 2 = (13 + 14)/ 2 = 27/ 2 = 13.5 (iii) Mode = 15 since it has maximum frequencies i.e. 37. The marks obtained by 120 students in a mathematics test is given below:
| Marks | No. of students |
| 0-10 | 5 |
| 10-20 | 9 |
| 20-30 | 16 |
| 30-40 | 22 |
| 40-50 | 26 |
| 50-60 | 18 |
| 60-70 | 11 |
| 70-80 | 6 |
| 80-90 | 4 |
| 90-100 | 3 |
Draw an ogive for the given distribution on a graph sheet. Use a suitable scale for your ogive. Use your ogive to estimate:
(i) the median
(ii) the number of students who obtained more than 75% in test.
(iii) the number of students who did not pass in the test if the pass percentage was 40.
(iv) the lower quartile
Solution:
| Marks | No. of students | c.f. |
| 0-10 | 5 | 5 |
| 10-20 | 9 | 14 |
| 20-30 | 16 | 30 |
| 30-40 | 22 | 52 |
| 40-50 | 26 | 78 |
| 50-60 | 18 | 96 |
| 60-70 | 11 | 107 |
| 70-80 | 6 | 113 |
| 80-90 | 4 | 117 |
| 90-100 | 3 | 120 |
(i) Median = (120 + 1)/ 2 = 60.5 th term Through mark 60.5, draw a parallel line to x-axis which meets the curve at A. From A draw a perpendicular to x-axis meeting it at B. Then, the value of point B is the median = 43 (ii) Number of students who obtained up to 75% marks in the test = 110 Number of students who obtained more than 75% marks in the test = 120 – 110 = 10 (iii) Number of students who obtained less than 40% marks in the test = 52 (from the graph; x = 40, y = 52) (iv) Lower quartile = Q 1 = 120 x (1/4) = 30 th term = 30
8. Using a graph paper, draw an ogive for the following distribution which shows a record of the width in kilograms of 200 students.
| Weight | Frequency |
| 40 – 45 | 5 |
| 45 – 50 | 17 |
| 50 – 55 | 22 |
| 55 – 60 | 45 |
| 60 – 65 | 51 |
| 65 – 70 | 31 |
| 70 – 75 | 20 |
| 75 – 80 | 9 |
Use your ogive to estimate the following:
(i) The percentage of students weighing 55 kg or more
(ii) The weight above which the heaviest 30% of the student fall
(iii) The number of students who are (a) underweight (b) overweight, if 55.70 kg is considered as standard weight.
Solution:
| Weight | Frequency | c. f. |
| 40-45 | 5 | 5 |
| 45-50 | 17 | 22 |
| 50-55 | 22 | 44 |
| 55-60 | 45 | 89 |
| 60-65 | 51 | 140 |
| 65-70 | 31 | 171 |
| 70-75 | 20 | 191 |
| 75-80 | 9 | 200 |
(i) The number of students weighing more than 55 kg = 200 – 44 = 156 Thus, the percentage of students weighing 55 kg or more = (156/200) x 100 = 78 % (ii) 30% of students = (30 x 200)/ 100 = 60 Heaviest 60students in weight = 9 + 21 + 30 = 60 Weight = 65 kg (From table) (iii) (a) underweight students when 55.70 kg is standard = 46 (approx.) from graph (b) overweight students when 55.70 kg is standard = 200 – 55.70 = 154 (approx.) from graph
9. The distribution, given below, shows the marks obtained by 25 students in an aptitude test. Find the mean, median and mode of the distribution.
| Marks obtained | 5 | 6 | 7 | 8 | 9 | 10 |
| No. of students | 3 | 9 | 6 | 4 | 2 | 1 |
Solution:
| Marks obtained(x) | No. of students (f) | c.f. | fx |
| 5 | 3 | 3 | 15 |
| 6 | 9 | 12 | 54 |
| 7 | 6 | 18 | 42 |
| 8 | 4 | 22 | 32 |
| 9 | 2 | 24 | 18 |
| 10 | 1 | 25 | 10 |
| Total | 25 | 171 |
10. The mean of the following distribution is 52 and the frequency of class interval 30 – 40 is ‘f’. Find f.
| Class Interval | 10 – 20 | 20 – 30 | 30 – 40 | 40 – 50 | 50 – 60 | 60 – 70 | 70 – 80 |
| Frequency | 5 | 3 | f | 7 | 2 | 6 | 13 |
Solution:
| C.I. | Frequency(f) | Mid value (x) | fx |
| 10-20 | 5 | 15 | 75 |
| 20-30 | 3 | 25 | 75 |
| 30-40 | f | 35 | 35f |
| 40-50 | 7 | 45 | 315 |
| 50-60 | 2 | 55 | 110 |
| 60-70 | 6 | 65 | 390 |
| 70-80 | 13 | 75 | 975 |
| Total | 36 + f | 1940 + 35f |
11. The monthly income of a group of 320 employees in a company is given below:
| Monthly Income (thousands) | No. of employees |
| 6 – 7 | 20 |
| 7 – 8 | 45 |
| 8 – 9 | 65 |
| 9 – 10 | 95 |
| 10 – 11 | 60 |
| 11 – 12 | 30 |
| 12 – 13 | 5 |
Draw an ogive of the given distribution on a graph paper taking 2 cm = Rs 1000 on one axis and 2 cm = 50 employees on the other axis. From the graph determine:
(i) the median wage.
(ii) number of employees whose income is below Rs 8500.
(iii) if salary of a senior employee is above Rs 11,500, find the number of senior employees in the company.
(iv) the upper quartile.
Solution:
| Monthly Income (thousands) | No. of employees (f) | Cumulative frequency |
| 6-7 | 20 | 20 |
| 7-8 | 45 | 65 |
| 8-9 | 65 | 130 |
| 9-10 | 95 | 225 |
| 10-11 | 60 | 285 |
| 11-12 | 30 | 315 |
| 12-13 | 5 | 320 |
| Total | 320 |
(i) Median = 320/2 = 160 th term Through mark 160, draw a parallel line to x-axis which meets the curve at A, From A draw a perpendicular to x-axis meeting it at B. The value of point B is the median = Rs 9.3 thousands (ii) The number of employees with income below Rs 8,500 = 95 (approx from the graph) (iii) Number of employees with income below Rs 11,500 = 305 (approx from the graph) Thus, the number of employees (senior employees) = 320 – 305 = 15 (iv) Upper quartile = Q 3 = 320 x (3/4) = 240 th term = 10.3 thousands = Rs 10,300The PDF link is available below for ICSE Class 10 Maths Selina Solutions Chapter 24. These solutions are designed to help students grasp the concepts clearly and perform well in their exams. Access the PDF to enhance your understanding and improve your performance in your studies.
ICSE Class 10 Maths Selina Solutions Chapter 24 PDF
As the ICSE Class 10 Board Exams have started from 17 February 2026 and the Mathematics exam is scheduled for 2 March 2026, revising Chapter 24 – Selina Solutions effectively in the last few days can boost confidence and help secure high marks. Here’s a focused strategy:
Revise Important Topics
Focus on all the key concepts and problem types in Chapter 24, including formulas, examples, and frequently asked questions. Prioritize high-weightage topics to ensure maximum scoring potential in the board exam.
Make Quick Notes
Create concise notes or flashcards of important formulas, theorems, and step-by-step methods for solving different types of problems. These will help in fast last-minute revision and quick recall during the exam.
Practice Problem Sets
Solve previous years’ questions, sample papers, and exercise problems from the chapter. Pay special attention to recurring question patterns and tricky sums to improve speed and accuracy.
Understand Concepts Clearly
Instead of memorizing steps blindly, focus on understanding the underlying concepts and logic behind each type of problem. Concept clarity ensures you can solve application-based and higher-order questions confidently.
