# ICSE Worksheet for chapter-9 Ratio Proportion class 9

## Find ICSE Worksheet for chapter-9 Ratio Proportion class 9

CLASS-9

BOARD: ICSE

Mathematic Worksheet - 9

TOPIC: Ratio Proportion

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#### SUMMARY:

• Compounded Ratio: The compounded ratio of the ratios (a:b), (c:d) and (e:f) is (ace:bdf).
• Duplicate Ratio: The duplicate ratio of (a:b) is (a2:b2)
• Sub-Duplicate Ratio: The sub-duplicate ratio of (a: b) is ( a(1/3) ∶ b(1/3))
• Triplicate Ratio: The Triplicate ratio of (a:b) is (a3:b3)
• Sub-Triplicate Ratio: The sub-triplicate ratio of (a: b) is ( )
• Componendo: If a/b=c/dthen, the componendo is (a+b)/b=(c+d)/d.
• Dividendo: If a/b=c/dthen, the dividendo is (a-b)/b=(c-d)/d.
• Componendo - Dividendo: If a/b=c/dthen, the componendo - dividendo is (a+b)/(a-b)=(c+d)/(c-d).

#### EXERCISE:

1. Find out:
1. the fourth proportional to 4, 9, 12;
2. the third proportional to 16 and 36;
3. the mean proportional between 0.08 and 0.18
2. If x: y = 3:4, find (4x+5y):(5x-2y)
3. Divide Rs. 1162 among A, B, C in the ratio 35:28:20
4. A bag contains 50p, 25p and 10p coins in the ratio 5:9:4, amounting to Rs.206. Find the no. of coins of each type.
5. If 1/5:1/x=1/x:1/125, then the value of x is:
1. 15
2. 20
3. 25
4. 35
6. If x:y=5:2 then (8x+9y):(8x+2y)
1. 22:29
2. 26:61
3. 29:22
4. 61:26
7. Two numbers are respectively 20% and 50% more than a third number. The ratio of the two numbers is:
1. 2:5
2. 3:5
3. 4:5
4. 6:7
8. The ratio of the number of boys and girls in a college is 7:8. If the percentage increase in the number of boys and girls be 20% and 10% respectively, what will be the new ratio?
1. 8:9
2. 17:18
3. 21:22
4. cannot be determined
9. What is the ratio whose terms differ by 40 and the measure of which is ?
1. 16:56
2. 14:56
3. 15:56
4. 16:72

### Solutions: to worksheet-9 Topic-Ratio Proportion

1. 27
2. 81
3. 0.12
1. 32/7
2. A=Rs.490; B= Rs. 392; C= Rs.280
3. 50p=200; 25p=360; 10p=160
4. (c)
5. (c)
6. (c)
7. (c)
8. (a)