Question

Six siblings arrive at a photographer’s studio to have pictures taken. In how many ways can the photographer arrange the six siblings for the photo?

Answer 1

There are n! ways of arranging n elements. This is because you have n possible choices for the first position, the remaining n-1 choices for the second position, and so on, until you're forced to pick the only remaining option.

So, there are

$6!=6\times 5\times 4\times 3\times 2$

ways of arranging 6 elements in a certain order.

Answer 2

The answer is definitely b