Question

The ratio of shoes sold to sandals was 5:2. if there were 40 sandals sold, how many shoes were sold?

Answer 1

It'd be best to put it into a proportion.
$\frac{2}{5} = \frac{40}{x}$
Cross multiply, divide by 2
The answer is 100 shoes.

Answer 2

100 is the answer and plz don't ask for the working out because i can't be bothered to show it