HELP PLS

There are 45 questions on your math exam. you answered 810 of them correctly. how many questions did you answer correctly?

You dug a hole that was 8 feet deep. after taking a short break, you dug down 3 more feet in the same hole. when finished digging, a tractor accidentally filled the hole with 4 feet of dirt. how deep is your hole now?

Which of the following scenarios demonstrates an exponential decay