Circle the standing coin Dori and Ariel are playing with Mr. Fin's coin collection. When taking two special coins they noticed that one of them has a radius five times larger than the other. They decide to leave the larger coin still and see how many turns the other coin takes to circle the standing coin. How many turns does the small coin make?

Attempt:  I found this reasoning from an exercise sheet: If the radius of the minor were "once larger than another" it would be $2r$. So five times bigger is $6r$.
is it correct?
answer: 6

The center of circle A moves around a circle with radius equal to the radius of $B$ plus the radius of $A$, which is $6r$. So the center of $A$ travels a distance of $2 \pi 6r$. The circle $A$ is rolling through this distance, each rotation covering $2\pi r$. Therefore, it takes 6 rotations to complete the path.

