Answer:
The three-person trip require more effort (row harder) than the two person-trip
Explanation:
The number of persons in the boat determines the mass of the boat
The mass of the boat with three people in total is more than the mass of the boat with only two person's
Mass is a measure of inertia, which is the resistance of a body to accelerate, and therefore, to the application of a force
Therefore, on the three-person trip were three people are in the boat, the boat has more mass, and therefore more inertia and will require more effort (force) than on the two-person trip that has a lesser mass