This is similar to Problem 2 from your Section 2.3 (part 2) worksheet.

Mario leaves Toad Town to visit Peach's Castle, traveling $3$ miles per hour. $5$ hours later, Luigi leaves Toad Town, also headed to Peach's Castle, traveling $9$ miles per hour. How long after Luigi leaves Toad Town will the brother meet?

The brothers will meet hour(s) after Luigi leaves Toad Town.

Hint:

Hint:

Hint: