A plane leaves New York for San Francisco and averages 800 km/h. At the same time, a plane leaves San Francisco for New York and averages 880 km/h. If the two cities are 5040 km apart, in how many hours will the planes pass each other?
A. 2.5
B.3
C.3.5
D.2
2006-12-22 10:11:32 · 3 answers · asked by mike 1 in Science & Mathematics ➔ Mathematics
Questions like these always are solved the same way...
Add the two speeds together, then divide the total distance by that. Essentially, you're saying, "When will the planes have travelled TOTAL of 5040km".
5040km / 1680km/h = 3 hr.
2006-12-22 14:53:07 · answer #1 · answered by TankAnswer 4 · 0⤊ 0⤋
b
the planes approaching each other at a speed of 800+880=1680 mph.
5040/1680=3
Therefore, they meet in 3 hours
2006-12-22 18:21:36 · answer #2 · answered by cnt 2 · 0⤊ 0⤋
800x+880x=5040
1680x=5040
x= 3
2006-12-22 18:15:34 · answer #3 · answered by 7 · 0⤊ 0⤋