Mental Floss 154

The answer to last week’s challenge is: Q: Two flexible wicks have been formed into torches. Each can burn exactly 60 minutes, but at a rate that is neither uniform nor predictable. How can you tell when 45 minutes have elapsed if you have nothing but matches at your disposal and no clock, ruler or scissors?

A: Light the first wick at both ends. At the same time light one end of the second wick. After half an hour the first wick will burn itself out. The second one will still have half an hour to burn. At this point, light the other side of it. After another 15 minutes have passed, the 2nd wick will burn out and you’ll know that 45 minutes have gone by.

This week’s challenge is:

Q: A young lad is playing around on the emergency ladder of his parent’s boat. His leg gets tangled in one of the rungs and he is left dangling above the water with his head 2.5 metres above the waterline. Unfortunately the tide is rising at a rate of 1 metre per hour. How much longer does he have to breathe?

The answer along with a new challenge, next week.

Have an excellent weekend …

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