A little help?

(v + 20)(t - 2) = vt = (v - 20)(t + 2).
Seems VERY unlikely, but I'll try it.

First equation implies 20t - 2v = 40;
second equation implies 2v - 20t = 40.
This implies that -40 = 40, which is absurd.

In general, increasing the speed is not going to decrease the time as much as decreasing the speed is going to increase the time. For example, if a train going 100 km/h covers 600 km in 6 hours, an increase of 20 km/h reduces that time to 5 hours, but a decrease of 20 km/h increases the time to 7.5 hours. There is no possible case where ANY speed and ANY distance results in the increments you posit. Are you sure you copied the question right?

Let V = the original speed. Velocity = dist/time. So we have V+ 20 = d/(t-2) and V-20 = d/(t+2) After working it out, though, I come to the same conclusion as az_lender. There is no solution, as stated.

d = distance
s = speed
t = time

d = s*t
d = (s-20)*(t+2)
d = (s+20)*(t-2)

3 equations, and 3 unknowns. Solve the unique solution.