The Cassette Recorder
You have only two hourglasses. The first one times exactly 7 minutes, the other times exactly 11 minutes.
Using just these two hourglasses and nothing else, how would you accurately time 15 minutes?
Related Brain Teaser:
You have only two hourglasses. The first one times exactly 7 minutes, the other times exactly 11 minutes.
Using just these two hourglasses and nothing else, how would you accurately time 15 minutes?
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A bit tricky this one, the solution is to: 1. Start both hourglasses at the same time. This gives: 7 minutes + 4 minutes + 4 minutes = 15 minutes. đź™‚
