Two students in the playground to practice long-distance race, a lap with 3min, B lap with 4min, the

Love Violet Fairy2010-01-31 10:01:15 +0000 #1

betrayer Illidan2010-01-31 10:12:50 +0000 #2

Solution: Let time x min

(1 / 3 + 1 / 4) x = 1

x = 12 / 7

A: 12 / 7 minutes after the encounter.

=. =

The most beautiful moment of KK2010-01-31 10:44:12 +0000 #3

4 / 7