Question

An Electrician want to fit 3156 lights in 12 newly built houses. Is there any lights left?

• A. Yes
• B. No

Answer 1

The correct option is B No

Given, number of lights he want to fit is $3156$.
Sum of digits of $3156=3+1+5+6=15$.
$\Rightarrow 3156$ is divisible by $3$.
Also, Last two digits of $3156$ i.e $56$ is divisible by $4$.
$\therefore 3156$ is also divisible by $4$.

So, we can say that if any number is divisible by $3$ and $4$ simultaneously then it is also divisible by $12$.

Hence, there will not be any lights left.