# At the start of the week, you could run for 8 minutes. By the end of the week, you could run for 15 minutes. Which proportion could you use to find the percent increase in your running time?

Jan 16, 2018

87.5% increase

#### Explanation:

The increase is the difference between the two times. So we have:

$\left(\text{change in time")/("original time")->("final time -original time")/("original time}\right) = \frac{x}{100}$
This gives us:

(15-8)/8=x/100color(white)("ddd") =>color(white)("ddd") x=7/8xx100 = 87.5%

color(white)("d")