Question

Daisy' single-speed bicycle has a front gear with 48 teeth and a rear gear with 12 teeth. If Daisy pedaled at 80 revolutions per minute(rpm), how fast her wheel rotate?

a.)280rpm
b.)320rpm
c.)70rpm
d.)128rpm

Answer 1

Daisy’s bicycle wheel will rotate at 320 rpm when she pedals at 80 rpm, given the gear ratio of 4:1 (48 teeth front gear to 12 teeth rear gear).

Step-by-step explanation:

The question is asking how fast Daisy's bicycle wheel will rotate if she pedals at 80 revolutions per minute (rpm) with a front gear of 48 teeth and a rear gear of 12 teeth. To solve this, we need to understand the gear ratio, which is the ratio of the number of teeth on the front gear (the chainring) to the number of teeth on the rear gear (the sprocket). The gear ratio is 48 teeth to 12 teeth, or 4:1. This means for every 1 turn of the pedals, the rear wheel will turn 4 times. Since Daisy pedals at 80 rpm, the rear wheel will turn at 80 rpm x 4, which equals 320 rpm. Therefore, option (b) is the correct answer.