Before the sale, the store had 100 pairs of flip flops in stock. After selling some, they notice that 1/4 of the flip flops they have left are blue. If the store has 40 pairs of blue flip flops, how many pair of flip flops (any color) have they sold?

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? *