Question

Why is the answer B? Plz explain.

Answer 1

You know that each person's share is $n$ dollars, and there are $m$ people in total.

So, if each of the $m$ people pays $n$ dollars, the total rent is $mn$ dollars.

For example, if you know that 7 people share the rent, and each of them pays 5 dollars, then the total rent is $7\cdot 5 = 35$ dollars.

So, if the total of $mn$ dollars is shared between $m^2$ people, each of them will pay

$\cfrac{mn}{m^2} = \cfrac{n}{m} \text{ dollars}$

Answer 2

m people each pay n dollars for a total rental of mn dollars.

If m^2 people share the cottage, then each one will pay

total/no. of people

=mn/m^2 = n/m dollars each, assuming there is no supplement for additional peole, as many hotels do.