Question

If $25*215*$ is divisible by $3$, then $*$ can take the value:

• A. $1$
• B. $3$
• C. $4$
• D. $5$

Answer 1

The correct option is B

$3$

Explanation for the correct option:

Option (b) $3$

We know that a number is divisible by $3$, if the sum of the digits of the given number is divisible by $3$.

Here, adding the digits of the given number we get $2+5+2+1+5=15$. But if we add $3$ to the $*$ given number, then the sum of the digits formed will be $21$ which is divisible by $3$.

Therefore, the $*$ can take the value as $3$.

Explanation for the incorrect option:

Option (a) $1$

We know that a number is divisible by $3$, if the sum of the digits of the given number is divisible by $3$.

Here, adding the digits of the given number we get $2+5+2+1+5=15$. But if we add $1$ to the $*$ given number, then the sum of the digits formed will be $17$ which is not divisible by $3$.

Option (c) $4$

We know that a number is divisible by $3$, if the sum of the digits of the given number is divisible by $3$.

Here, adding the digits of the given number we get $2+5+2+1+5=15$. But if we add $4$ to the $*$ given number, then the sum of the digits formed will be $23$ which is not divisible by $3$.

Option (d) $5$

We know that a number is divisible by $3$, if the sum of the digits of the given number is divisible by $3$.

Here, adding the digits of the given number we get $2+5+2+1+5=15$. But if we add $5$ to the $*$ given number, then the sum of the digits formed will be $25$ which is not divisible by $3$.

Hence, the Correct Option is (b) $3$