The boat went against the current 66.15 km in 4.9 hours how long it would take

The boat went against the current 66.15 km in 4.9 hours how long it would take for it to return if the speed if its own speed is 16.2 km / h.

1) Let’s designate the speed of the boat k = 16.2 km / h and the speed of the current “t”, and compose the following equalities:

66.15 km / 4.9 h = 13.5 km / h = k – t = 16.2 – t.

2) From here we determine the speed of the current t:

t = 15.2 km / h – 13.5 km / h = 2.7 km / h.

3) Now you can determine the time of movement with the flow, first by determining the speed with the flow:

(k + t) = 16.2 km / h + 2.7 km / h = 18.9 km / h.

4) The travel time on the way back is equal to:

66.15 km: 18.9 km / h = 3.5 hours.

Answer: the return trip will take 3.5 hours.