Find each unknown number. a. 12 is 150% of what number? b. 5 is 50% of what number? c. 10% of what number is 300? d. 5% of what number is 72? e. 20 is 80% of what number?

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? *