Sandi and Felipe are participating in a Walk for Life to raise money for charity. Sandi will raise $30, plus $2.50 for each mile she walks. Felipe will raise $20, plus $5 for each mile he walks. The total amount that each will raise can be calculated using the following expressions, where n stands for the number of miles walked: Sandi: 30 + 2.5n Felipe: 20 + 5n After how many miles will Sandi and Felipe have raised the same amount of money?