Can anyone please help?:((

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.)

Aculture started with 3000 bacteria. after 5 hours it grew to 3900 bacteria. predict how many bacteria will be present after 9 hours

Kyle and elijah are planning a road trip to california. their car travels 3/4 of a mile per min. if they did not stop driving, how many miles could kyle and elijah drove in a whole day? ? 1 day = 24 hours. plzzz write a proportion i will give you 100 points