Question

How many numbers lie between the squares of
(a) $20$ and $21$
(b) $20$ and $30$

• A. $a\left)41b\right)500$
• B. $a\left)40b\right)499$
• C. $a\left)40b\right)500$
• D. $a\left)41b\right)499$

Answer 1

The correct option is B $a\left)40b\right)499$

$\left(a\right){20}^2=400{21}^2=441\therefore numberofnumbers=(441-400)-1=40\left(b\right){20}^2=400{30}^2=900\therefore numberofnumbers=(900-400)-1=499$