Question

Kelli’s mom takes a 400 mg dose of aspirin. Each hour, the amount of aspirin in a person’s system decreases by

about 29%. How much aspirin is left in her system after 6 hours?

Answer 1

Answer: 51.2 mg

Explanation:

The exponential equation to represent decay:-

`y=A(1-r)^t` , where A is the initial value , r is the rate of decay and t is the time period.

As per given, we have

A= 400 and r= 29%=0.29

Put theses values in the above formula.

The amount left after t hours:

`y=400(1-0.29)^t=400(0.71)^t`

Put t=6 , we get

`y=400(0.71)^6=400(0.128100283921)\\\\=51.2401135684\approx51.2\ mg`

Hence, the amount of aspirin is left in her system after 6 hours= 51.2 mg