One skier covered the distance of 20 km 20 minutes faster than the other skier. Find the speed of both skiers if one of them is travelling 2 km/hour faster than the other one.

1 answer

speed of slower --- x km/h
speed of faster ---- x+2 km/h

20/x - 20/(x+2) = 20/60 = 1/3
times 3x(x+2) , the LCD

60(x+2) - 60x = x(x+2)
x^2 + 2x - 120 = 0
(x+12)(x-10) = 0
x = 10 or x = -12, the ladder is silly

The slower one went 10 km/h, and the faster went 12 km/h

check:
20/10 - 20/12
= 1/3 hr or 20 minutes.
My answer is correct