To get the product 1, we should multiply 8/21 with
(a) 8/21
(b) -8/21
(c) 21/8
(d) -21/8

Solution:

Given number 8/21

Let the number be x

(8/21) × (x) = 1

x = 1/ 8/21

x = 21/8

Therefore, the required number is 21/8.

✦ Try This: To get the product 1, we should multiply 4/7 with_______.

Given number is 4/7

Let the other number be x

(4/7) × (x) = 1

x = 7/4

☛ Also Check: NCERT Solutions for Class 8 Maths Chapter 1

NCERT Exemplar Class 8 Maths Chapter 1 Problem 12

To get the product 1, we should multiply 8/21 with (a) 8/21, (b) -8/21, (c) 21/8, (d) -21/8

Summary:

To get the product 1, we should multiply 8/21 with 21/8

☛ Related Questions:

• - (-x) is same as (a) - x, (b) x, (c) 1/x, (d) -1/x
• The multiplicative inverse of -1 1/7 is (a) 8/7, (b) -8/7, (c) 7/8, (d) -7/8
• If x be any rational number then x + 0 is equal to (a) x, (b) 0, (c) - x, (d) Not defined