Question

Twenty-four pencils cost $1.20, how much will six pencils cost? Which proportion can be used to find the cost, c, of six pencils?

A. c/24 = 1.20/6
B. c/6 = 1.20/24
C. 24/c = 6/1.20
D. 6/c = 24/1.20

Answer 1

The cost of six pencils can be calculated using the proportion c/6 = 1.20/24. After setting up the proportion correctly, cross-multiplication and division lead to the cost of six pencils being $0.30.

Step-by-step explanation:

The question asks to determine the cost of six pencils, given the cost of twenty-four pencils. To solve this, we can use a proportion which shows the relationship between the number of pencils and their cost.

The correct proportion is: B. c/6 = 1.20/24. This is because we are trying to find the cost c for 6 pencils, and we are given the cost for 24 pencils, which is $1.20. The proportion is set up by comparing the cost per pencil between the two quantities.

To solve for c, we cross-multiply and divide:
6 × 1.20 = 24 × c
7.20 = 24c
Dividing both sides by 24, we get:
c = 7.20 / 24
c = $0.30

Therefore, the cost of six pencils is $0.30.