Aditya Gupta
Last Activity: 5 Years ago
the answer would be 18.3
let us assume that immediately after the nth dose is taken, the amount of medicine in body be Mn ml.
4 hours after the nth dose is taken, the medicine will be 25% or 1/4th less.
so it will be Mn – Mn/4= 3Mn/4.
since 4 hours have passed, the person will now consume n+1 th dose of 6 ml.
hence, Mn+1= 3Mn/4 + 6
this is a recurrence relation. also, we know that M1= 6.
so we can find out M2, using that M3, then M4 and finally M5, which turns out to be 2343/128= 18.3ml.