Question

Matt ran 40 miles one week. The second week, he decreased his weekly mileage by 25%. How many miles did Matt run during the second week?

Answer 1

In this problem 40 miles correspound to the 100%, so we can use a rule of 3 to calculate how many miles correspound to 25% and then we rest that from the total.

so the rule of three will be:

$\begin{gathered} 40\to100 \\ x\to25 \end{gathered}$

and the equation will be:

$\begin{gathered} x=\frac{40\cdot25}{100} \\ x=10 \end{gathered}$

So the second week Matt ran:

$40-10=30$

Matt ran 30 miles