Question

A boat travels upstream for 168 miles in 4 hours and returns in 3 hours traveling downstream in a local stream of water. What is the rate of the boat in still water and the rate of the current? The rate of the boat in still water is ___miles per hour. The rate of the current is ____ miles per hour.

a) 20; 12
b) 18; 10
c) 25; 15
d) 22; 14

Answer 1

The rate of the boat in still water is 49 miles per hour and the rate of the current is 7 miles per hour.

Step-by-step explanation:

To find the rate of the boat in still water and the rate of the current, we can use the formula:

Rate of boat in still water = (rate downstream + rate upstream)/2

Rate of current = (rate downstream - rate upstream)/2

In this case, the boat travels upstream for 168 miles in 4 hours, which gives us a rate of 42 miles per hour. The boat then returns downstream in 3 hours, which gives us a rate of 56 miles per hour. Using the formulas, we can calculate:

Rate of boat in still water = (56 + 42)/2 = 49 miles per hour

Rate of current = (56 - 42)/2 = 7 miles per hour

Therefore, the rate of the boat in still water is 49 miles per hour and the rate of the current is 7 miles per hour.