And will give medal!

a chain fits tightly around two gears as shown. what is the radius of the smaller gear? round your answer to the nearest tenth
a. 23.2
b.4.8
c.9.2
d.14.0

Abicycle training wheel has a radius of 3 inches. the bicycle wheel has a radius of 10 inches.approximately how much smaller, in square inches and rounded to the nearest hundredth, is the area of the training wheel than the area of the regular wheel? *