Question

A recipe for 10 bran muffins calls for 1 cup of flour. The number of muffins that can be made varies directly with the amount of flour used. There are 3 1/2 cups of flour available. How many muffins can be made?

Answer 1

35

Explanation:

For 1 cup of flour, you make 10 muffins. Just by reading the problem, you see that the number of muffins, 10, is 10 times the number of cups of flour, 1.

For 3 1/2 cups of flour, you make 10 times that number muffins.

3 1/2 × 10 = 3.5 × 10 = 35

Answer: 35 muffins

You can also use a proportion.

1 cup flour is to 10 muffins as 3.5 cups flour is to x muffins.

1/10 = 3.5/x

Cross multiply:

1 × x = 10 × 3.5

x = 35

Answer: 35 muffins

Answer 2

35

Explanation:

3 1/2 x 10 =35

make 3 1/2 into an improper fraction: 3 x 2 + 1 = 7/2

make 10 into a fraction: 10/1

find the LCD (least common denominator) for each number:

10/1 = 20/2

7/2 = 7/2

20/2 x 7/2 = 70/2 = 35

:)