Answer: 5 hours
Explanation:
Since Chau works at a constant rate, we need to first find the unit price. We can do this by dividing 119/7 which equals 17. So Chau earns $17 per hour. Next we need to find how long he needs to work to earn $85. We can do that by dividing 85/17 which equals 5 hours.
So the answer is 5 hours.