My son is doing an Algebra I course and has come across an issue with a word problem. I used to excell at math, but apparently that knowledge has begun to slip my mind. Anyhow, here's the problem and any assistance would be appreciated.

Solve each problem using the two given facts.

1. Find the number of full 8 hour shifts that Maria worked last month.

(1) She worked twice as many 6 hour shifts as 8 hour shifts.

(2) She worked a total of 280 hours.