Circumference

sooooooooooo close. Stay with it and use your calculator.

One hint: 80 times what equals 1 mile?

Distance to the Pub?

5280/80 = 66

???

NO! A carriage wheels' circumferences have a 4:5 ratio. The front wheel makes 80 revolutions more than the rear wheel in 1 mile. So - 80 represents 1/5 of the revolutions the small wheel (because 4x80 how may times the large wheel revolves for the same mile). If you can;t take it from there...........

Not sure.

recent studies show that women seem to prefer circumference to length, especially in one night stands

wait, isn't this one of those never ending dating questions

never mind

I don't teach by induction. What value are you trying solve?

C for Circumference.

Apparently, Randy can't..

So, if 80 revolutions are 1/5 of the small wheel total revolutions in one mile, how many revolutions does it take to make a mile?

Small wheel revolutions = 80*5=400.

As the wheels' ratio is 5:4, then the large wheel will make 80*4 = 320 revolutions.

If 400 revolutions are done in 1 mile, translating to feet it will be:

F = 5280/400 = 13.2 ft

and

B = 5280/320 = 16.5 ft

Divide by Pi to know their diameters.

Thank you. The ratio was confusing me. Please explain ratio in more detail.

Well, let's try:


- A ratio shows the relative sizes of two values, here the circumference of the wheels.

If the ratio of the wheels is 5:4, it means that the smaller wheel is 20% smaller than the large one.

How?

The difference between the larger and the smaller wheel is:

5-4=1

If 5 is 100% than 1 is 100/5=20%.

And the smaller is 100%-20% = 80% of the larger one.

This means that when the larger wheel makes a revolution, the smaller one has to make 20% more to do the same distance.

In our case:

16.5*20% = 3.3 ft

13.2 + 3.3 = 16.5 ft.

And 20% of 400 = 80 revolutions.

Let's hope it's clear..

Thanks. I understand it now.