## Thursday, August 04, 2005

Busy day today so open for solutions now. Next puzzle coming shortly.

A young Buddhist is told by his master to meditate for exactly 45 minutes. However, all he is given to keep time is two incense sticks and some matches. Each of the incense sticks, upon being lit, will burn completely in exactly one hour, but they are cheaply made and don't burn uniformly.

How can the student arrange to meditate for exactly 45 minutes?

OutEast said...

He can't. He'll be too busy dicking about with the joss sticks to meditate.

Anonymous said...

"...all he is given to keep time..."

solution: He could look at his own watch.

Jon Dursi said...

He tells the shop owner `I will trade you these two fine Buddhist incense sticks for that clock...'

Perhaps it could work like this...

The monk lights both ends of the first stick and just one end of the second stick. After 30 minutes the first stick will be finished, leaving the second stick half burned.

At this point the monk lights the other end of the remaining, half-burned stick, allowing it to burn itself out in 15 minutes.

Since 30 minutes plus 15 minutes is the required 45, that should leave us with a satisfied monk.

CC said...

While I applaud your mathematics and logical analysis, I'm sure that referring to a "satisfied monk" is unnecessarily suggestive. If you catch my drift.

David said...

"The monk lights both ends of the first stick and just one end of the second stick. After 30 minutes the first stick will be finished, leaving the second stick half burned.

At this point the monk lights the other end of the remaining, half-burned stick, allowing it to burn itself out in 15 minutes.

Since 30 minutes plus 15 minutes is the required 45, that should leave us with a satisfied monk."

O.K., I am an idiot, so please bear with me. The first stick burns out in 30 minutes. The second stick burns as well for 30 minutes. How does the remaining half of the second stick now burn for only 15 minutes? Half of it burned in 30 minutes, and now the other half will burn in only 15?

I am sure this is obvious to everyone, but mathematical word problems are, to say the least, not easy for my tiny brain.

CC said...

"How does the remaining half of the second stick now burn for only 15 minutes? Half of it burned in 30 minutes, and now the other half will burn in only 15?"

Because it's now burning from both ends at once.

David said...

Ahh, yes. Well, that was an embarrassing demonstration of reading comprehension on my part.