algebra 1
posted by Victoria .
A passenger plane and a jet leave att the same time from the same airport,traveling in opposite directions. The jet travels at twice the speed of the passenger plane. they are 2400 mi apart in 4 hours. Find the speed of the passenger plane and jet.

speed of passenger  x mph
speed of jet 2x mph
they each went for 4 hours, so
distance covered by jet = 4(2x) = 8x
distance covered by pass = 4x
8x + 4x = 2400
12x = 2400
x = 200
passenger plane went 200 mph, and the jet went 400 mph
Just noticed that I answered the same question back in Nov of 2007
http://www.jiskha.com/display.cgi?id=1194411287