Difference between Problem and Exercise

I just watched a university lecture about problem solving. How long do we take to solve a problem, less than a second, a minute, an hour, a day, a month , a year or a life time.

The professor poses a problem as follows:-

a. The doctor categorically says that the drug will work if you take it religiously everyday.

b. The drug consists of two type of pills, i.e. Pill A and Pill B.

c. You are required to take only one pill each of A and B at the same time.

d. Any imbalance of dosage taken will kill you.

E.g.

A + A = fatal

B + B = fatal

A+A+B= fatal

B+B+A=fatal

A alone = fatal

B alone = fatal

A + B = OK

B + A = OK

e. There is no marking on the pill and both pill A and B are identical in look.

f. One day, while taking a phone call, you happen to drop 2 A's and 1 B in your palm.

g. As the pills are identical to each other, you have no way to isolate the pill A and pill B.

g. If you take 2 A's and 1 B, it will end your life.

How do you solve this problem ?

Clue to this problem:

This problem can become an exercise for those who have wishful thinking.

I have googled the internet and could not find any solution. Do you want to slow down the emergence of Alzhemier's disease.