Multiple choice general knowledge math & puzzles

A doctor gives you three pills telling you to take one every half hour. How many minutes would the pills last?

  1. 90

  2. 60

  3. 120

  4. 150
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Take the first pill at time 0, the second pill 30 minutes later, and the third pill another 30 minutes later (at 60 minutes). The three pills span a 60-minute period. A common mistake is multiplying 3 pills × 30 minutes = 90 minutes, but the first pill is taken immediately.

AI explanation

The trick is that the first pill is taken immediately (time zero), the second 30 minutes later, and the third 30 minutes after that — so only two 30-minute intervals occur between the three doses. That gives a total elapsed time of 60 minutes, not 90, since you don't wait an extra half hour after the last pill.

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