perplexus.info :: Just Math : The hour-glass

The hour-glass (Posted on 2009-01-20)

An hour-glass is formed by two identical cones.

Initially, the top cone is full of sand, and the bottom cone is empty.

The sand starts flowing down at a constant rate and the top cone is emptied in exactly 1:30 hours.

How long does it take for the height of the sand in the bottom cone be half of the height in the top cone?

See The Solution Submitted by pcbouhid

Rating: 2.5000 (2 votes)

Comments: ( You must be logged in to post comments.)

Subject	Author	Date
No Subject	Glenn Howard	2023-10-05 07:14:01
Puzzle Answer	K Sengupta	2023-10-05 00:34:33
re: Sand vs. Water?	Charlie	2009-01-21 11:24:18
Sand vs. Water?	rod hines	2009-01-20 17:21:29
solution	Charlie	2009-01-20 12:43:59

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