What is the quickest way to time a 9 minute cooking session with two sand-glasses of 4 and 7 minutes respectively?
Post your answer and calculations below.
EMBED:
A riddle to challenge your mind | Back – Next | Arrange the numbers 1-9
Thought-provoking Feature Brainteaser. Do you remember your prime numbers?
A simple but unusual paragraph. Can you spot anything odd about it?
Doug had forgotten the 5 digit code to his briefcase. However, he did remember five clues: The fifth number plus the third number equals fourteen; The fourth number is one…
Weekly brain teaser. Do you remember Algebra?
Is the LEED certification here for the long haul, or is it just a fad?
Is it really necessary to become a LEED accredited professional (LEED AP)? Can you design for sustainability without having LEED accreditation? Is this just another acronym to put on a business card? Or, as some suggest, is this a half hearted attempt by the U.S. Green Building Council (USGBC) to exploit the demand for solutions to environmental issues and make some money along the way?
An 8-inch model screw, tested in a water tunnel at a rotational speed of 22.5 revolutions per second and a velocity of flow of 12 feet per second, yields a…
You must be logged in to post a comment.
This site uses Akismet to reduce spam. Learn how your comment data is processed.
Tell your cook to do it 🙂
At Time=0
Start both 4 & 7 Timer
At Time= 4
Restart The (4 min.) Timer
At Time = 7
Restart The (7 Min.) Timer
** Begin The Cooking
At Time = 8
(When The 7 Min. timer run out)
restart the 4 min. timer
At time= 12
restart the 4 min. timer
So : the cooking time = 1 + 4+ 4 = 9 min.
Good job everyone,
Here is my solution. It is fairly similar to some of yours.
Start both timers simultaneously, then turn the 4 minute one over as soon as it runs out. Then when the 7 minute timer runs out, turn it over. When the 4 minute timer runs out for the second time, turn over the 7 minute timer which has been running for 1 minute, and when it runs out, hey presto 9 minutes have elapsed.
Thanks.
Ken.