Plane A leaves the airport......

Question

Plane A leaves the airport. One hour later, Plane B leaves the same airport on the same course. It catches up to Plane A in 2.5 hrs. The average speed of Plane B is 300 km/h faster than Plane A. Find the speed of each plane.

Answer 1

3.5r = 2.5(r+300)

3.5r = 2.5r + 750

r = 750 <--- that's fast

750+300 = 1050 <--- planes go that fast?

Answer 2

Use the formula d=rt for each plane.

Plane A:

3.5r=r x 3.5

Plane B:

2.5r+750=(r+300)2.5

Both planes flew the same distances so set the equation of the d of plane A is equal to the d of plane b.

3.5r=2.5r+750

-2.5 -2.5

r=750 (rate of plane A)

750+300=1050 (rate of plane b)