For a swimmer who swims the length

L

of a swimming pool at

1.5(m)/(s)

in

t1

seconds and returns to the starting point at

1.2(m)/(s)

in 2 seconds. The return trip to the starting point is 20 seconds longer than the first part of the swim.

For a swimmer who swims the length L of a swimming pool at 1.5m/s in t1 seconds and returns to the starting point at 1.2m/s in t2 seconds. The return trip to the starting point is 20 seconds longer than the first part of the swim