HELP PLEASE MATH ALGEBRA

Initially 100 milligrams of a radioactive substance was present. after 6 hours the mass had decreased by 4%. if the rate of decay is proportional to the amount of the substance present at time t, find the amount remaining after 24 hours. (round your answer to one decimal place.)

Ben bowled 124 and 188 in his first two games. what must he bowl in his third game to have an average of at least 160?

15/16 as a decimal rounded to the nearest hundredth