How would you prove two circles are similar

Suppose that one doll house uses the 1 inch scale, meaning that 1 inch on the doll house corresponds to 1/2 foot for life-sized objects. if the doll house is 108 inches wide, what is the width of the full-sized house that it's modeled after? in inches and feet.

A50% increase followed by 33 1/2% decrease

What is 1/3x5 on anuber line what does it look like on a number line