Question

An excellent swimmer is confident he can judge his speed in the water exactly. He bets he can swim two lengths of a 50-meter Olympic size pool at an average speed of precisely 2 meters per second. On his first lane he is a little bit slow and ends up going at 1.5 meters per second. Which average speed does he have to reach on his second lane to win the bet?

Answer 1

(1.5 + x) / 2 = 2 .... multiply both sides by 2
1.5 + x = 2 * 2
1.5 + x = 4
x = 4 - 1.5
x = 2.5 meters per second