Question

To place leaves Kansas City at 1 PM. Plane A heads east at 450 mph and plane B heads due west at 600 mph. How long will it be before the planes are 2100 miles apart?

A: 1 hour
B: 2 hours
C: 3 hours
D: 4 hours

Answer 1

The planes will be 2100 miles apart after 2 hours.

Step-by-step explanation:

To find out how long it will take for the planes to be 2100 miles apart, we need to calculate the time it takes for them to reach that distance.

The total speed at which the planes are moving away from each other is the sum of their speeds: 450 mph + 600 mph = 1050 mph.

To find the time it takes, we divide the total distance they need to cover (2100 miles) by their combined speed: 2100 miles / 1050 mph = 2 hours.

Therefore, the correct answer is B: 2 hours.