Bob gave half his football collection to Joh. He then bought 10 more footballs. If Bob now has 20 footballs, how many did he start with? a. 12 b. 10 c. 20 d. 5

The train station clock runs too fast and gains 5 minutes every 10 days. how many minutes and seconds will it have gained at the end of 9 days?

2x minus y equals 6, x plus y equals negative 3

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? *