Please help me figure these questions out

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.)

Could somebody me with this radical simplification?

Answer asap ill give ! ’ a sample of radioactive material decays over time. the number of grams, y , of the material remaining x days after the sample is discovered is given by the equation y = 10(0.5)^x. what does the number 10 represents in the equation? a. the half-life of the radioactive material, in days b. the amount of the sample, in grams, that decays each day c. the time, in days, it will take for the samples to decay completely d. the size of the sample, in grams, at the time the material was discovered