Question

a number is as much greater than 21 as less than 71. Find the number

Answer 1

n-21=71-n 
2n=92 
n=46
so 46 is the answer

Answer 2

Let the number be x.

ATQ,
x - 21 = 71 - x
⇒ x + x =  71 + 21
⇒ 2x = 92
⇒ x = 92/2
⇒ x = 46

The number is 46.