Math Help - A few algebra questions

1. A few algebra questions

A biathlon event involves running and cycling. I can cycle 30km/h faster than I run. I spend 48 minutes running and a third as much time again cycling in an event. The event covers a total distance of 60km. How fast do I run?

A real estate agent sells 22 houses in six months. He makes a commission of $11,500 per house on some and$13000 per house on remainder. If his total commission over the six months was $272,500, on how many houses did he make a commission of$11,500?

How do I do these :S

2. What have you come up with so far?