Question

If a recipe for a cake calls for 2 1/2 cups of flour and mary wishes to make 3 cakes, how many cups of flour does she need?

Answer 1

To make 3 cakes,we multiply the flour needed by three,and here's the equation:
$2 \frac{1}{2} \times 3 \\ = \frac{5}{2} \times 3 \\ = \frac{15}{2} \\ = 7 \frac{1}{2}$
Thus, she'll need 7 and 1/2 cups of flour.

hope it helps!