You take a 325 milligram dosage of ibuprofen. During each subsequent hour, the amount of medication in your bloodstream decreases by about 29% each hour.

a. Write an exponential decay model giving the amount y (in milligrams) of ibuprofen in your bloodstream t hours the initial dose.

b. Estimate how long it takes for you to have 100 milligrams of ibuprofen in your bloodstream. Round your answer to the nearest tenth