The radius and height of a cylinder are each multipled by 2. What is the change in the total surface area of the cylinder?

The "normal" surface area would be

2*pi*r (r + h)

The "new" surface area would be

2*pi*(2r) (2r + 2h)=

2*pi*(2r)(2)(r + h)=

8*pi *r (r + h) =  4 times as great