Question

The probability that Caroline wins a raffle is given by the expression

Answer 1

Answer:  $\frac{n-m}{n}$

This is the same as writing (n-m)/n

Don't forget about the parenthesis if you go with the second option.

==================================================

Explanation:

The probability that she wins is m/n, where m,n are placeholders for positive whole numbers.

For instance, m = 2 and n = 5 leads to m/n = 2/5. This would mean that out of n = 5 chances, she wins m = 2 times.

The probability of her not winning is 1 - (m/n). We subtract the probability of winning from 1 to get the probability of losing.

We could leave the answer like this, but your teacher says that the answer must be "in the form of a combined single fraction".

Doing a bit of algebra would have these steps

$1 - \frac{m}{n}\\\\\frac{n}{n} - \frac{m}{n}\\\\\frac{n-m}{n}$

and now the expression is one single fraction.