Question

The number of calories consumed from an apple is directly proportional to the number of apples eaten. If 4 apples contain 380 total calories, how many apples would you have to eat to reach a total of 1,045 calories?

Answer 1

Explanation:

The direct proportion equation is y = kx which reads, "y is directly proportional to x". k is the constant of proportionality. In our case, we read this is as, "the number of calories is directly proportional to the number of apples eaten." Our equation would look like c = ka. We first are given that a = 4 and = 380. We will use that to solve for k:

380 = k4 so

k = 95. Now that know the value of k, we will use that along with the number of calories (1045) to find the number of apples, a:

1045 = 95a so

a = 11

This means that it will be 11 apples that contain 1045 calories.