Question

Check whether $2^2+2^3+2^4$ is divisible by $2$ or $4$ or by both $2$ and $4$?

Answer 1

We can write given Equation as
$2^2+2^3+2^4=2^2(1+2+2^2)=4(1+2+4)=4\times 7=28$
Therefore it is divisible by both $4$ and $2$ as $4=2\times 2$