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}](https://img.qammunity.org/2023/formulas/mathematics/college/43lwm1akho9mcbk3u264o366ij4t4pr64r.png)
and the equation will be:
![\begin{gathered} x=(40\cdot25)/(100) \\ x=10 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/x2ej0gusobpjxr47btg6wqvq5rfmdq06p5.png)
So the second week Matt ran:
![40-10=30](https://img.qammunity.org/2023/formulas/mathematics/college/re63bj7td64gkilytqquuh4ryvsh2bic2q.png)
Matt ran 30 miles