Alice and Bert start running around a track, in opposite directions. Alice runs 3 meters per second faster than Bert. They meet after 30 seconds, and Alice completes her lap in another 20 seconds. How many seconds does it take Bert to complete one full lap of the track?
+36916 When they meet, they have covered one full lap of the track together
they meet at 30 seconds, then
alice takes 20 more seconds for a total of 50 seconds per lap
alice has covered 3/5 and bert has only covered 2/5 of a lap
2/5 x = 30 seconds
x = 75 sec for bert -lap
