Answer:
Speed of slower plane = 400 mph
Speed of the faster plane = 440 mph
Step-by-step explanation:
Let x be the speed of the slower plane, in mph.
Thus; the speed of the other plane is x +40 mph.
The distance between two planes decreases at the rate;
x + (x+40) = 2x + 40 mph.
We get the equation
1680/(2X + 40) = 2.
Solve the equation;
We multiply both sides by (2x + 40), to get
1680 = 2*(2x + 40),
1680 = 4x + 80,
4x = 1600.
Hence,
x = 1600/4
= 400 mph.
Therefore; the speed of the slower airplane is 400 mph, while
The speed of the faster is 400 + 40 = 440 mph.
