Question

A dozen doughnuts cost $15. At this rate how much would 7 doughnuts cost?

Answer 1

Answer: $8.75

Explanation:

We can create a proportion to solve. Let the numerator be the number of donuts, the denominator be the cost, and x be the cost of 7 doughnuts.

Given:

`\displaystyle (12)/(15) =(7)/(x)`

Cross-multiply:

12 * x = 15 * 7

Multiply:

12x = 105

Divide both sides of the equation by 12:

x = 8.75

The cost of 7 doughnuts would be $8.75 at this rate.