Question

The digit at ones place of the number is $5$. If the number lies between $\text{100 and 150}$ will it be a composite or a prime?

Answer 1

In this question, we have to check the number ending with $5$between $\text{100 and 150}$ are composite or prime numbers.

First write the numbers ending with $5$ between $\text{100 and 150}$.

Numbers are $\text{105, 115, 125, 135 and 145}$

All these numbers have more than two factors

For e.g. some factors of $105$are $1,5,105$ etc

some factors of $135$ are $1,5,135$ etc

Hence, the numbers ending with $5$ between $\text{100 and 150}$ should be composite