Circumference and Perimeter

Here's the third one......

Circumference of coaster = 2pi (radius)

12.56  = 2pi (radius)    divide by 2pi

12.56 / [ 2pi] = radius =    6.28/pi  inches

Then....the radius of the glass  =  [ 6.28/pi -  1/2] inches

So......the circumference of the glass =

2 * pi * radius  =

2 * pi * [ 6.28/pi - 1/2) ]  ≈ 9.42 in 

Here's the frist one :

The linear distance traced out by one revolution of the ball will be

 2* pi (1 inch)  = 2pi inches

And 5 ft  = 60 inches

So......,the number of revolutions  =  60 / [ 2 pi]   =  30 / pi ≈ 9.5 revolutions