What was the question for this implicit rationale, and corresponding answer?
It cost 2 * 1.5 = $3 a day. So it cost 3 * 30 = $90 per day. Insurance covers 90 * .4 = $36. So he pays 90 - 36 = $54 a month.
 The answer: 54
The question: John needs to take 2 pills a day. One pill costs $1.5. The insurance covers 40% of the cost. How much does he pay in a 30-day month?