Question

Please could somebody give me some advice.

Cog A has 8 teeth and connects with cog B which has 10 teeth. A ratio of 8:10 or 2:5 at its lowest.

If A completes 10 turns, how many turns does B complete?

I get this to be 8 at a ratio of 8:10 or 1:0.8
Is this correct?

What is the least number of turns that A can complete so that B also completes an exact number of turns?

I get this to be 5 at a ratio of 5:4
Is this correct?

B completes 30 turns. On how many occations will both A and B have been back in their starting position at the same time?

I get this to be 6 at a ratio of 2:5
Is this correct?

Any comments gratefully received.