Question

Which two consecutive whole numbers is the value of √21 between?

Answer 1

The answer is:  [A]:  " 4 and 5 " .
______________________________
Explanation:
______________________________
Looking at the answers:
______________________________
 we know that 4² = 16 ; and 5² = 25 ;

So:  √16 = 4  ;  and √25 = 5.

So:  √21 must be between √16 and √25 ;

That is: √21 must be between 4 and 5 ; which is answer choice:  [A] .
__________________________________________________________

Answer 2

The perfect squares on either side of 21 are 16 and 25 of which the roots are:

4 and 5