Question

A class of 23 students are going on a trip through some beautiful woods with their teacher. They suddenly come upon a river that is too wide to cross by foot. Luckily, there is a canoe nearby! The canoe is able to carry four people in it, however, it requires an adult to steer. How many trips back and forth across the river would it take for the entire class to cross the river using the one canoe?

Answer 1

It would take 8 trips.

Explanation:

The teacher will always have to be on the canoe, meaning that there are only 3 seats left for the kids. 7 trips would only take 21 of the kids, and 8 would take all, and have one empty seat the last time.

Answer 2

6 trips back and fourth

Explanation: