Need help with math its a struggle

Kevin is an insurance salesman. when he sells a policy, he makes 20 percent of the policy premium (p) up front; then each year the policy is active, he receives 15 percent of the original premium. which equation could be used to figure his total commission on a policy that has been active for five years? c=0.80p c=0.20p + 0.15p c=0.35p + 4(0.15) c=0.95p

One of the inventors of integrated circuits observed that the number of transistors that fit on an integrated circuit will double every 24 months. what type of relationship most appropriately models this situation?

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