Consider an example with car travel. To find the rate of car travel, take the distance traveled and divide by the time it took. For example, let's say we traveled 30 miles in 2 hours:
distance = 30 miles
time = 2 hours
rate = distance / time = (30 miles) / 2 (hours) = 15 miles/hour
If I then ask you, how long would it take to travel 45 miles, you would divide by the rate we found in step 1. For example,
45 miles ÷ 15 miles/hour = 3 hours
Now try the same approach with this problem. Good luck!