Question

The following picture shows two gears meshed together with the arrows lined up. Gear A has 48 teeth, while gear B has 28 teeth. Suppose the gears begin turning. How many complete revolutions would gear B need to make before the arrows are lined up again?

Answer 1

Answer: 12

Explanation:

The LCM of 48 and 28 is 336

It would take 336 ÷ 28 = 12 revolutions of gear B

and 336 ÷ 48 = 7 revolutions of gear A

to match up the arrows.