9514 1404 393
Answer:
3 hours
Explanation:
After 1 hour, the planes are separated by a distance of 180 +330 = 510 miles. At that rate, the time it takes for them to be 1530 miles apart is ...
time = distance/speed
time = (1530 mi)/(510 mi/h) = 3 h
After 3 hours, the planes will be 1530 miles apart.