
RS Aggarwal Solutions for Class 8 Maths Chapter 3 Exercise 3.4: The Physics Wallah academic team has provided a comprehensive answer for Chapter 3: Squares and Square Roots in the RS Aggarwal class 8 textbook. Read the theory of chapter-3 Squares and Square Roots before attempting to solve all of the numerical problems in exercise-3D.
One must have a thorough understanding of chapter-3 Squares and Square Roots before proceeding with the solution of Exercise-3D. For class 8 maths students, the NCERT textbook is a highly recommended resource for solving numerical problems and referencing NCERT solutions.RS Aggarwal Solutions for Class 8 Maths Chapter 3 Exercise 3.4 PDF
Find the square root of each of the following numbers by using the method of prime fraction:
(1) 225
Solution: By prime factorization,
225 = 3 × 3 × 5 × 5 ∴ √225 = (3 × 5) = 15.(2) 441 = 3 × 3 × 7 × 7
∴ √441 = (3 × 7) = 21.(3) 729 = 3 × 3 × 3 × 3 × 3 × 3
∴ √729 = (3 × 3 × 3) = 27.(4) 1296 = 2 × 2 × 2 × 2 × 3 × 3 × 3 × 3
∴ √1296 = (2 × 2 × 3 × 3) = 36.(5) 2025 = 3 × 3 × 3 × 3 × 5 × 5
∴ √2025 = (3 × 3 × 3 × 5) = 45.(6) 4096 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2
∴ √4096 = (2 × 2 × 2 × 2 × 2 × 2) = 64.(7) 7056 = 2 × 2 × 2 × 2 × 3 × 3 × 7 × 7
∴ √7056 = (2 × 2 × 3 × 7) = 84.(8) 8100 = 2 × 2 × 3 × 3 × 3 × 3 × 5 × 5
∴ √8100 = (2 × 3 × 3 × 5) = 90.(9) 9216 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 3 × 3
∴ √9216 = 2 × 2 × 2 × 2 × 2 × 3 = 96.(10) 11025 = 3 × 3 × 5 × 5 × 7 × 7
∴ √11025 = (3 × 5 × 7) = 105.(11) 15876 = 2 × 2 × 3 × 3 × 3 × 3 × 7 × 7
∴ √15876 = (2 × 3 × 3 × 7) = 126.(12) 17424 = 2 × 2 × 2 × 2 × 3 × 3 × 11 ×11
∴ √17424 = (2 × 2 × 3 × 11) = 132.(13) Find the smallest number by which 252 must be multiplied to get a perfect square. Also, find the square root the perfect square so obtained.
Solution: By prime factorization, we get
252 = 2 × 2 × 3 × 3 × 7 So, the given number should be multiplied by 7to make the product a perfect square. New number = 252 × 7 = 1764 ∴ 1764 = 2 × 2 × 3 × 3 × 7 × 7 √1764 = 2 × 3 × 7 = 42(14) Find the smallest number by which 2925 must be divided to obtain a perfect square. Also find the square root of the perfect square so obtained.
Solution: By prime factorization, we get
2925 = 3 × 3 × 5 × 5 × 13 So, the given number should be divided by 13 to make the product a perfect square. New number = 2925 ÷ 13 = 225 ∴ 225 = 3 × 3 × 5 × 5 √225 = 3 × 5 = 15(15) 1225 plants are to be planted in a garden in such a way that each row contains as many plants as the number of rows. Find the number of rows and the number of plants in each row.
Solution: Let the number of row be x.
∴ x 2 = 1225 or, x = √1225 or, x = 5 × 7 = 35 Hence, the number of the rows is 35.(16) The students of a class arranged a picnic. Each student contributed is Rs 1156, find the strength of the class.
Solution: Let the number of students be x.
∴ x 2 = 1156 or, x = √1156 or, x = 2 × 17 = 34(17) Find the least square number which is exactly divisible by each of the numbers 6, 9, 15 and 20.
Solution: The least number divisible by each one of 6, 9, 15 and 20 is their LCM.
Now, LCM of 6, 9, 15 and 20 = (2 × 3 × 5 × 3 × 2) = 180. By prime factorization, we get 180 = 2 × 2 × 3 × 3 × 5 To make it perfect square it must be multiplied by 5. Hence, required number = (180 × 5) = 900.(18) Find the least square number which is exactly divisible by each of the numbers 8, 12, 15 and 20.
Solution: The least number divisible by each one of 8, 12, 15 and 20 is their LCM.
Now, LCM of 8, 12, 15, 20 = (2 × 2 × 3 × 5 × 2) = 120. By prime factorization, we get 120 = 2 × 2 × 2 × 3 × 5 To make it a perfect square it must be multiplied by (2 × 3 × 5), i.e., 30. Hence, required number = (120 × 30) = 3600.Enhanced Understanding : The solutions provide detailed, step-by-step explanations for each problem, helping students understand the underlying concepts of squares and square roots thoroughly.
Practice and Reinforcement : With a variety of problems, students get ample practice, which reinforces their learning and helps them retain the concepts better.
Problem-Solving Skills : The exercise includes different types of questions, from basic calculations to complex word problems, which enhance students' problem-solving skills and analytical thinking.
Error Identification : By comparing their answers with the solutions, students can identify and correct their mistakes, leading to improved accuracy in their work.
Exam Preparation : The solutions align with the curriculum and are designed to prepare students for exams by covering all possible question types that might appear in tests and exams.
Confidence Building : Understanding and solving the problems correctly boosts students' confidence in their mathematical abilities, encouraging them to tackle more challenging problems.
