Problema Solution
There is a ground of 1km. Person A takes 2 minutes to complete one round. Person B takes 2.5 minutes to complete one round. They decide to do a race of 20 rounds on the same ground. They start at the same time. How many times does Person B overtake Person A during the race?
Answer provided by our tutors
20 rounds equals distance of 10 km.
Person A's rate is 1/2 = 0.5 km/min
Person B's rate is 1/2.5 = 0.4 km/min
Peron B overtakes Person A every 1/(0.5 - 0.4) = 10 min.
Since they compete 20 rounds, this means that person A will complete the rounds in 20*2 = 40 min.
40 : 10 = 4, meaning that A will overcome B 4 times.