Class 9 Maths Exercise 1.5 | Number System | NCERT Simple Solutions

Overview

There are 3 questions in Class 9 Maths Exercise 1.5. The questions and their solutions are explained in easy language.

Question/Answers Class 9 Maths Exercise 1.5

S.No.	Question/Answers
Q.1.	Find: (i) 64½ (ii) 32⅕ (iii) 125⅓
Ans.	(i) 64½ = (8²)½ = 81 (as 2×1/2 =1) = 8 (ii) 32⅕ = (2⁵)⅕ = 21 (as 5×1/5 =1 = 2 (iii) 125⅓ = (5³)⅓ = 51 (as 3×1/3 =1) = 5
Q.2.	Find: (i) 93/2 (ii) 32⅖ (iii) 16¾ (iv) 125-1/3
Ans.	(i) 93/2 = (32)3/2 = 33 (as 2×3/2 = 3) = 27 (ii) 322/5 = (25)2/5 = 22 (as 5×2/5 = 2) = 4 (iii) 163/4 = (24)3/4 = 23 (as 4×3/4 =3) = 8 (iv) 125-1/3 = (53)-1/3 = 5-1 (as 3x-1/3 = -1) = ⅕
Q.3.	Simplify: (i) 22/3 . 21/5 (ii) (1/33)7 (iii) 111/2/111/4 (iv) 71/2 . 81/2
Ans.	(i) 22/3 . 21/5 = 22/3+1/5 = 213/15 [as 2/3+1/5 = (10+3)/15 = 13/15 ] (ii) (1/33)7 = (3-3 )7 = 3-21 = 1/321 [as -3×7= -21] (iii) 111/2/111/4 = 111/2 – 1/4 = 112/8 = 111/4 [as 1/2-1/4 = (4-2)/8 = 2/8 = 1/4] (iv) 71/2 . 81/2 = (7 x 8)1/2 = 561/2

Extra Questions

Q.1. Find the value of 2√3 + √3
Ans. 2√3 + √3 = √3 ( 2+1) = 3√3

Q.2. If x = 7+ √40, Find the value of √x + 1/√x .

Other Maths Concepts

To understand maths concepts of Rational numbers, Integers, etc used in NCERT Class 9 Maths Exercise 1.5, please also check the following articles:

1. What are Rational and Irrational Numbers
2. What are Natural Numbers
3. What are Integers
4. What are Whole Numbers