Question

Find which of the following numbers are divisible by $3$.​

(i) $221$​

Answer 1

Given number $=221$​

​We know that, ​A number is divisible by $3$, if the sum of its digits is divisible by $3$.​
$\text{Sum of digits}=2+2+1=5$

Since $5$ is not divisible by $3$.​
​Hence, $221$ is not divisible by $3$.​