Question

Find the number of natural numbers lying between ${18}^2$ & ${19}^2$.

• A. $18$
• B. $36$
• C. $37$
• D. $48$

Answer 1

The correct option is B $36$

Number of natural numbers lying between $n^2$ and $(n+1{)}^2=(n+1{)}^2-n^2-1=2n$

Therefore, number of natural numbers lying between ${18}^2$ and ${19}^2$ $=2n=2\times 18=36$ numbers.