Tony and Maria are training for a race by running all the way up and down a 700m long ski slope. They each run up the slope at different constant speeds. Coming down the slope, each runs at double his or her uphill speed. Maria reaches the top first, and immediately starts running back down, meeting Tony 70m from the top. When Maria reaches the bottom, how far behind is Tony?
(A)140m (B)250m (C)280m (D)300m (E)320m
Let Maria's speed be x and 2x for uphill and downhill respectively
Let Tony's speed be y and 2y for uphill and downhill respectively
When they met (time taken was the same)
Time = distance/speed
700/x + 70/2x = 630/y
1470/2x = ...
This is a word problem regarding different speeds.