A boat's crew rowed 7.5 miles downstream, with the current, in 1.5 hours. the return trip upstream, against the current, covered the same distance, but took 2.5 hours. find the crew's average rowing velocity in still water and the average velocity of the current.

Average rowing velocity of boat in still water is 4 miles per hour and average velocity of the current is 1 mile per hour.

Step-by-step explanation:

We are given the following in the question:

Let x be the average rowing velocity of boat in still water and y be the the average velocity of the current.

The boat rowed 7.5 miles downstream, with the current, in 1.5 hours.

Velocity with the current =

Thus, we can write the equation:

The return trip upstream, against the current, covered the same distance, but took 2.5 hours.

Velocity against the current =

Thus, we can write the equation:

Solving, the two equations:

Thus, average rowing velocity of boat in still water is 4 miles per hour and average velocity of the current is 1 mile per hour.