How do you do this?? could you also show your work pls..

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years

Adan has decided to purchase an $9000 car. he plans on putting 20% down toward the purchase and financing the rest at 7.9% interest rate for 3 years. find his monthly payment a) $225.29 b) $298.81 c) $204.78 d) $236.89

Wholesome food company has been hired to design a healthy menu for the cafeteria at ridgemont high school. they want to conduct a survey to determine what percentage of ridgemont’s 15001500 students like broccoli. the survey will ask, “do you like broccoli? ”