How do i do this?

A25-inch wide drum is used in a marching band. what area does the top of the drum cover? round to the nearest hundredth. (use 3.14 for pi.)

An internet company charges $8.95 per month for the first 3 months that it hosts your web site. then the company charges $11.95 per month for web hosting. how much money, in dollars, will the company charge for 8 months of web hosting?

What is 100,000 times 1/100,000, using the standard method of multiplication? write the answer as 10 to a power.