There are two wheels with diameter 30 inches and 20 inches. The first wheel covers a certain distance in 240 revolutions. In how many revoluions would the second wheel cover the same distance?

Answer 1

dwould it be proportional? The linear distances their circumferences are in a set proportion.

30/240=20/N

Answer 2

bobpursley,

Thanks for your responce and help, I don't think so it's proportional. Since the answer is 360 revolutions.
And putting them in proportions doesn't give the correct answer.

A friend told me this solution;
Find the circumference of both the wheels by formula 2 pi r:

1st wheel: 94.2 inches.
2nd wheel: 62.8 inches.

Now multiply the circumference of the 1st wheel by revolutions:
94.2*240 = 22608 inches.

This would be the otal distance traveled by wheels.

Now divide the distance by the circumference of second wheel,
you'll get no. of revolutions:

No. of revolutions: 22608/62.8
No. of revolutions: 360 revolutions.