Question

A motor boat traveling at 18 miles per hour traveled the length of a lake in one-quarter of an hour less time than it took when traveling at 12 miles per hour. What was the length in miles of the lake?

a) 24
b) 36
c) 48
d) 72

Answer 1

To find the length of the lake, we can set up an equation using the formula: time = distance / speed. Solving the equation, we find that the length of the lake is 9 miles.

Step-by-step explanation:

To solve this problem, we can use the formula: time = distance / speed. Let's assume that the length of the lake is 'd' miles.

When the boat is traveling at 18 miles per hour, the time it takes is given by: (d / 18) hours.

When the boat is traveling at 12 miles per hour, the time it takes is given by: (d / 12) hours.

We are given that the first time is one-quarter of an hour less than the second time. So, we can write the equation: (d / 18) = (d / 12) - (1/4).

Simplifying the equation, we have: 2d = 3d - 9.

Therefore, d = 9 miles, which means that the length of the lake is 9 miles.