Question

Suppose the drug atenolol is taken in 25 mg doses once a day to lower blood pressure. At the end of a 24 hour period, approximately 7 % of the atenolol is still present.
a) Find expressions for the quantities. Q1, Q2, Q3, and Qn., representing the amounts of atenolol in the body right after taking the 1st, 2nd, 3rd doses respectively. Then write the expression for. Qn. in closed-form.

Answer 1

You just have to write it as an arithmetic progression:

$Q_{n} = \frac{ 0.07^{n+1}-1}{0.07-1}$

This is the general formula for Qn and to find Q1, Q2... you replace the n with the number.