Question

A study showed that the ratio of the number of people who get their news from print sources to the number of people who get their news from social media sources is 3:7. Based on the ratio, how many people in a town of 900 people get their news from social media sources?

Two classmates solved this problem and their work is shown below. Which classmate solved the problem correctly? Explain the error in the classmate who solved it incorrectly.

Answer 1

270 = number who get news from print sources

630 = number who get news from social media

Explanation:

Let 3x = number who get news from print sources

and 7x = number who get news from social media

Then 3x + 7x = 900

10x = 900

x = 90

3x = 3(90) = 270 = number who get news from print sources

7x = 7(90) = 630 = number who get news from social media

Check: 270/630 = 3/7 and 270 + 630 = 900