Question

A circular jogging track forms the edge of a circular lake that has a diameter of 2 miles. Johanna walked once around the track at the average rate of 3 miles per hour. If t represents the number of hours it took Johanna to walk completely around the lake, which of the following is a correct statement?

A. 0.5
B. 1.75
C. 2.0
D. 2.5
E. 3

Answer 1

Given:

Diameter of lake = 2 miles

∴
`Radius = (Diameter)/(2)` = 1 miles

The circumference of the lake can be computed as :

Circumference = 2πr

Circumference = 2×3.14×1 = 6.28 miles

This circumference is the total distance traveled by Johanna.

We are give the speed at which Johanna jogs, i.e. Speed = 3 miles/hour

∴ Time taken by Johanna to jog around the lake is given as :

`Time = (Distance)/(Speed)`

Time = 2.093 hours

∴ The correct option is (c.)