Two planes, which are 3950 miles apart, fly toward each other. Their speeds differ by 40mph. If they pass each other in 5 hours, what is the speed of each?

Question

Two planes, which are 3950 miles apart, fly toward each other. Their speeds differ by 40mph. If they pass each other in 5 hours, what is the speed of each?

Answer 1

Let x be the speed of the slower plane, in mph.
The 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 can write equation as

 

3950 / 2x+40 =  5

 

3950 = 10x+200

 

10x = 3750

 

x = 375

 

the speed of the slower plane = x = 375  mph.
The the speed of the other plane is x +40=375 +40 = 415 mph.

 

 

Answer 2

Hi, Jane.

So the first plane is traveling X mph

the 2nd plane is traveling (X + 40)mph

when their total distances equal 3950 miles, they will pass each other.

Distance = rate x time

time = 5 hours

5X + 5(X + 40) = 3950

 

10X + 200 = 3950

10X = 3750

X = 375

So, the first plane is going 375 mph

the 2nd plane is going 415 mph