Answer: 51.2 mg
Step-by-step explanation:
The exponential equation to represent decay:-
, 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:

Put t=6 , we get

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