Kinematics Question: A motorboat and a log in a stream

[dudu]

Homework Statement

A river flows with a uniform velocity v. A person in a motorboat travels 1.9km upstream, at which time she passes a log floating by. Always with the same throttle setting, the boater continues to travel upstream for another 60.8min and then returns downstream to her starting point, which she reaches just as the same log does. Calculate the velocity of the river.

Relevant Equations

listed below

I found vlog=1.9/t and vb-v=1.15/t and vb+v=d+1.15/60.8 don't know what to do now

 

[PeroK]

What is the purpose of the log, do you think?

 

[Hamiltonian]

have you considered trying to solve the question in the reference frame of the river?

 

[Lnewqban]

Welcome, dudu!

Could you verfy that no originally provided information is missing?
Where that 1.15 and that d and v come from?