Question

A family has five members--a mom, a dad, two sisters, and a brother.The family lines up single file. What is the probability that the mom is at the front of the line?

Answer 1

To find the probability that the mom is at the front of the line:

$\frac{number \: of \: favorable \: outcomes}{total \: outcomes} \\ = \frac{number \: of \: ways \: where \: mum \: is \: at \: the \: front \: of \: the \: line}{total \: number \: of \: ways} \\ = \frac{1c1 ×4! }{5!} \\ = \frac{24}{120} \\ = \frac{1}{5}$
Therefore the answer is 1/5.

Hope it helps!