RS Aggarwal Solutions for Class 8 Maths Chapter 3 Exercise 3.1: The Physics Wallah academic team has provided a comprehensive answer for Chapter 3: Squares and Square Roots in the RS Aggarwal class 8 textbook. The RS Aggarwal class 8 solution for Chapter 3 Squares and Square Roots Exercise-3A is uploaded for reference only; do not copy the solutions.
Before going through the solution of Chapter Squares and Square Roots Exercise-3A, one must have a clear understanding of the chapter-3 Squares and Square Roots. Read the theory of Chapter 3 Squares and Square Roots and then try to solve all numerical of exercise-3A. 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 3.1 PDF
(1) Using the prime factorization method, find which of the following numbers are perfect squares:
(i) 441 = 3 × 3 × 7 × 7 = 3 2 × 7 2 (ii) 576 = 2 × 2 × 2 × 2 × 2 × 2 × 3 × 3 = 2 6 × 3 2 (iii) 11025 = 5 × 5 × 3 × 3 × 7 × 7 = 5 2 × 3 2 × 7 2 (iv) 1176 = 2 × 2 × 2 × 3 × 7 × 7 (v) 5625 = 3 × 3 × 5 × 5 × 5 × 5 = 3 2 × 5 4 (vi) 9075 = 3 × 5 × 5 × 11 × 11 (vii) 4225 = 5 × 5 × 13 × 13 = 5 2 × 13 2 (viii) 1089 = 3 × 3 × 11 × 11 = 3 2 × 11 2(2) Show that each of the following numbers is a perfect square. In each case, find the number whose square is the given number:
(i) 1225 = 5 × 5 × 7 × 7 = 5 2 × 7 2
Thus, 1225 is the product of pairs of equal factors. ∴ 1225 is a perfect square. Also = (5 × 7) 2 = (35) 2 Hence, 35 is the number whose square is 1225.(ii) 2601 = 3 × 3 × 17 × 17 = 3 2 × 17 2
Thus, 2601 is the product of pairs of equal factors. ∴ 2601 is a perfect square. Also = (3 × 17) 2 = (51) 2 Hence, 51 is the number whose square is 2601.(iii) 5929 = 7 × 7 × 11 × 11 = 7 2 × 11 2
Thus, 5929 is the product of pairs of equal factors. ∴ 5929 is a perfect square. Also = (7 × 11) 2 = (77) 2 Hence, 77 is the number whose square is 5929.(iv) 7056 = 2 × 2 × 2 × 2 × 3 × 3 × 7 × 7 = 2 2 × 2 2 × 3 2 × 7 2
Thus, 7056 is the product of pairs of equal factors. ∴ 7056 is a perfect square. Also = (2 × 2 × 3 × 7) 2 = (84) 2 Hence, 84 is the number whose square is 7056.(v) 8281 = 7 × 7 × 13 × 13 = 7 2 × 13 2
Thus, 8281 is the product of pairs of equal factors. ∴ 8281 is a perfect square. Also = (7 × 13) 2 = (91) 2 Hence, 91 is the number whose square is 8281.(3) By what least number should the given number be multiplied to get a perfect square number? In each case, find the number whose square is the new number.
(i) 3675
Solution: Resolving 3675 into prime factors, we get
3675 = 3 × 5 × 5 × 7 × 7 = (3 × 5 2 × 7 2 ) Thus, to get a perfect square number, the given number should be multiplied by 3. New number = (3 2 × 5 2 × 7 2 ) = (3 × 5 × 7) 2 = (105) 2 Hence, the number whose square is the new number = 105.(ii) 2156
Solution: Resolving 2156 into prime factors, we get
2156 = 2 × 2 × 7 × 7 × 11 Thus, to get a perfect square number, the given number should be multiplied by 11. New number = (2 2 × 7 2 × 11 2 ) = (2 × 7 × 11) 2 = (154) 2 Hence, the number whose square is the new number = 154.(iii) 3332
Solution: Resolving 3332 into prime factors, we get
3332 = 2 × 2 × 7 × 7 × 17 Thus, to get a perfect square number, the given number should be multiplied by 17. New number = (2 2 × 7 2 × 17 2 ) = (2 × 7 × 17) 2 = (238) 2 Hence, the number whose square is the new number = 238.(iv) 2925
Solution: Resolving 2925 into prime factors, we get
2925 = 3 × 3 × 5 × 5 × 13 Thus, to get a perfect square number, the given number should be multiplied by 13. New number = (3 2 × 5 2 × 13 2 ) = (3 × 5 × 13) 2 = (195) 2 Hence, the number whose square is the new number = 195.(v) 9075
Solution: Resolving 9075 into prime factors, we get
9075 = 3 × 5 × 5 × 11 × 11 Thus, to get a perfect square number, the given number should be multiplied by 3. New number = (3 2 × 5 2 × 11 2 ) = (3 × 5 × 11) 2 = (165) 2 Hence, the number whose square is the new number = 165.(vi) 7623
Solution: Resolving 7623 into prime factors, we get
7623 = 3 × 3 × 7 × 11 × 11 Thus, to get a perfect square number, the given number should be multiplied by 7. New number = (3 2 × 7 2 × 11 2 ) = (3 × 7 × 11) 2 = (231) 2 Hence, the number whose square is the new number = 231.(vii) 3380
Solution: Resolving 3380 into prime factors, we get
3380 = 2 × 2 × 5 × 13 × 13 Thus, to get a perfect square number, the given number should be multiplied by 5. New number = (2 2 × 5 2 × 13 2 ) = (2 × 5 × 13) 2 = (130) 2 Hence, the number whose square is the new number = 130.(viii) 2475
Solution: Resolving 2475 into prime factors, we get
2475 = 3 × 3 × 5 × 5 × 11 Thus, to get a perfect square number, the given number should be multiplied by 11. New number = (3 2 × 5 2 × 11 2 ) = (3 × 5 × 11) 2 = (165) 2 Hence, the number whose square is the new number = 165.(4) By what least number should the given number be divided to get a perfect square number? In each case, find the number whose square is the new number.
(i) 1575
Solution: Resolving 1575 into prime factors, we get
1575 = 3 × 3 × 5 × 5 × 7 = (3 2 × 5 2 × 7) Thus, to get a perfect square number, the given number should be divided by 7. New number obtained = (3 2 × 5 2 ) = (3 × 5) 2 = (15) 2 Hence, the number whose square is the new number = 15.(ii) 9075
Solution: Resolving 9075 into prime factors, we get
9075 = 3 × 5 × 5 × 11 × 11 = (3 × 5 2 × 11 2 ) Thus, to get a perfect square number, the given number should be divided by 3. New number obtained = (5 2 × 11 2 ) = (5 × 11) 2 = (55) 2 Hence, the number whose square is the new number = 55.(iii) 4851
Solution: Resolving 4851 into prime factors, we get
4851 = 3 × 3 × 7 × 7 × 11 = (3 2 × 7 2 × 11) Thus, to get a perfect square number, the given number should be divided by 11. New number obtained = (3 2 × 7 2 ) = (3 × 7) 2 = (21) 2 Hence, the number whose square is the new number = 21.(iv) 3380
Solution: Resolving 3380 into prime factors, we get
3380 = 2 × 2 × 5 × 13 × 13 = (2 2 × 5 × 13 2 ) Thus, to get a perfect square number, the given number should be divided by 5. New number obtained = (2 2 × 13 2 ) = (2 × 13) 2 = (26) 2 Hence, the number whose square is the new number = 26.(v) 4500
Solution: Resolving 4500 into prime factors, we get
4500 = 2 × 2 × 3 × 3 × 5 × 5 × 5 = (2 2 × 3 2 × 5 × 5 2 ) Thus, to get a perfect square number, the given number should be divided by 5. New number obtained = (2 2 × 3 2 × 5 2 ) = (2 × 3 × 5) 2 = (30) 2 Hence, the number whose square is the new number = 30.(vi) 7776
Solution: Resolving 7776 into prime factors, we get
7776 = 2 × 2 × 2 × 2 × 2 × 3 × 3 × 3 × 3 × 3 = (2 2 × 2 2 × 2 × 3 × 3 2 × 3 2 ) Thus, to get a perfect square number, the given number should be divided by 2 × 3. New number obtained = (2 2 × 2 2 × 3 2 × 3 2 ) = (2 × 2 × 3 × 3) 2 = (36) 2 Hence, the number whose square is the new number = 36.(vii) 8820
Solution: Resolving 8820 into prime factors, we get
8820 = 2 × 2 × 3 × 3 × 5 × 7 × 7 = (2 2 × 3 2 × 5 × 7 2 ) Thus, to get a perfect square number, the given number should be divided by 5. New number obtained = (2 2 × 3 2 × 7 2 ) = (2 × 3 × 7) 2 = (42) 2 Hence, the number whose square is the new number = 42.(viii) 4056
Solution: Resolving 4056 into prime factors, we get
4500 = 2 × 2 × 2 × 3 × 13 × 13 = (2 2 × 2 × 3 × 13 2 ) Thus, to get a perfect square number, the given number should be divided by 2 × 3. New number obtained = (2 2 × 13 2 ) = (2 × 13) 2 = (26) 2 Hence, the number whose square is the new number = 26.(5) Find the largest number of 2 digits which is a perfect square.
Ans: The largest 2-digit number is 99. Square of 10 = 100 > 99, thus the number would be less than 10. And the largest whole number less than 10 is 9. Therefore, 9 × 9 = 81(6) Find the largest number of 3 digits which is a perfect square.
Ans: The largest three digits number is 999. But 961 is a largest three digits number, is a perfect square.
961 = 31 × 31 Here, for easy to understand we take the before and after number of 31. Those are 30 and 32 respectively. Now, 30 × 30 = 900 and 32 × 32 = 1024. Hence, we can write 961 is largest three numbers has a perfect square.Concept Clarity : The solutions offer clear and detailed explanations for each problem, helping students understand the fundamental concepts of squares and square roots thoroughly.
Step-by-Step Guidance : Each solution is broken down into step-by-step instructions, making it easier for students to follow along and grasp the procedures involved in solving problems related to squares and square roots.
Reinforcement of Learning : By practicing with these solutions, students reinforce their understanding of squares and square roots, ensuring that they retain the concepts for longer and can apply them in different contexts.
Error Correction : The detailed solutions help students identify where they might have gone wrong in their calculations and understand the correct approach, reducing the likelihood of repeating the same mistakes.
Improved Problem-Solving Skills : The variety of problems presented in Exercise 3.1 helps students develop their problem-solving skills, encouraging logical thinking and analytical reasoning.
Exam Preparation : The solutions are aligned with the exam syllabus and pattern, making them a valuable resource for exam preparation. Students become familiar with the types of questions that may appear in exams and learn the best methods to solve them.