Question

Two planes left the same airport traveling in opposite directions. The first plane left the airport at 2 P.M. traveling at an average rate of 500 mph. The second plane left the airport at 4 P.M. traveling at an average rate of 550 mph. When will the planes be 3100 miles apart?

Answer 1

ok so the first plane has 2 hours head start
means 2 times 500=1000=1000mile head start
so now

3100-1000=2100

in how many hours will the conbined planes travel 2100
500+550=1050
1050 times how many hours=2100
divide both sides by 1050
hours=2
4pm was our base time
4+2=6
answer is 6PM