May is swimming steadily in a pool. She completes 5 laps in 4 minutes. Joy is also swimming in the same direction and she swims 4 laps in 5 minutes. At 10 AM Joy just head of May. At 10:15 AM, how many times will May pass Joy?

To answer this question, we need to find the difference in time it takes for May and Joy to swim a certain number of laps. Let's calculate the time it takes for May to complete each lap and the time it takes for Joy to complete each lap.

May completes 5 laps in 4 minutes, so she takes an average of 4/5 = 0.8 minutes per lap.
Joy completes 4 laps in 5 minutes, so she takes an average of 5/4 = 1.25 minutes per lap.

Now let's compare the distance each swimmer covers in a fixed time interval. From 10 AM to 10:15 AM, there are 15 minutes.

May can complete 15/0.8 = 18.75 laps in this time.

Joy can complete 15/1.25 = 12 laps in this time.

Since Joy was ahead of May at 10 AM, May will need to catch up to Joy and surpass her. The number of times May passes Joy will be the difference between May's 18.75 laps and Joy's 12 laps.

Therefore, May will pass Joy 18.75 - 12 = 6.75 times.

However, since we can't have a fractional number of laps, May will actually pass Joy 6 times during this time interval.

So the answer is: At 10:15 AM, May will pass Joy 6 times.