Question

Howard uses 2/5 of a bag of flour to make a sheet cake. How many bags of flour would he need to make 3 1/2 sheet cakes?

MULTIPLE CHOICE
a) 3 9/10 bags b) 3 1/10 bags c) 3 bags d) 1 2/5 bags e) 1 2/7 bags

Answer 1

1 2/5 bags

Explanation:

We can use ratios to solve

2/5 bag x bags

------------ = ---------------

1 cake 3 1/2 cakes

Change to an improper fraction

2/5 bag x bags

------------ = ---------------

1 cake 7/2 cakes

Using cross products

2/5 * 7/2 = 1 *x

7/5 =x

Changing back to a mixed number

1 2/5 bags