**Hour Glass Puzzle - 29 October**

I have two sand hour glasses:

1. A 7 minute one and

2. An 11 minute one.

Using just these 2 sand hour glasses, how can i measure time as 15 minutes ?

**For Solution :**Click Here

This Blog is a collection of brain teasers, puzzles (maths,fun,brain etc), riddles,Questions, Quiz.

I have two sand hour glasses:

1. A 7 minute one and

2. An 11 minute one.

Using just these 2 sand hour glasses, how can i measure time as 15 minutes ?

Subscribe to:
Post Comments (Atom)

Difficulty Level 3/5
(726)
Logic Puzzles
(483)
Difficulty Level 4/5
(455)
Riddles
(364)
Difficulty Level 2/5
(358)
Maths Puzzles
(344)
Picture Puzzles
(328)
Trick Teasers
(282)
Popular Puzzles
(212)
Rebus Puzzles
(155)
Humor Puzzles
(151)
Interview Puzzle
(124)
Series Puzzles
(124)
What Word Am I
(99)
Difficulty Level 1/5
(90)
Trivia
(76)
Mystery Puzzles
(73)
Equation Puzzles
(72)
Difficulty level 5/5
(53)
Murder Mystery Puzzles
(43)
Square Count
(40)
Probability Puzzles
(39)
Who Am I
(39)
IAS-EXAMS
(34)
Cipher Puzzles
(32)
Algebra
(31)
Science Puzzles
(30)
Situation Puzzles
(28)
Puzzles of Age
(21)
Read Between Lines Puzzles
(18)
Google Interview Puzzle
(17)
Microsoft Interview Puzzles
(15)
statement
(15)
MatchSticks-Riddles
(14)
Time Distance Problem
(14)
Odd One Out
(13)
Relationship Puzzles
(11)
Cards
(10)
Story Puzzles
(10)
Paradox Puzzles
(9)
Classic
(6)
Directional Puzzles
(6)
Best Of 2011
(5)
clever
(5)
Brain-Twister
(4)
Mind Games
(4)
Analytical
(3)
What Does This Text Mean
(3)
CHALLENGING
(2)
Double Meaning
(2)
Acronym
(1)
Measure
(1)
Suduko
(1)
Video Riddle
(1)
chess
(1)
coin-Puzzles
(1)
m
(1)
pop
(1)
triv
(1)

0:00

ReplyDeleteFlip both hourglasses

7:00

The 7 min hourglass runs out. Flip it back over.

The 11 min hourglass has 4 minutes remaining. Let it keep running.

11:00

The 7 min hourglass has 3 mins left. Flip it over, and it has 4 mins.

The 11 min hourglass is now empty. Leave it.

15:00

The 7 min hourglass runs out.

seems correct

DeleteStart both hourglasses together. When 7 min hourglass runs out (and the 11 min hourglass has four minutes left), start counting time from minute 0.

ReplyDeleteNow, 11 min hourglass will run four 4 minutes, then flip it over and let it run for its full duration of 11 minutes. This will measure 4 + 11 = 15 minutes.

Start with both 11 and 7 glass hors. By the time 11 glass hour completes one round 7 would have completed one round in a direction and 4 in the other direction.

ReplyDeleteSo by the end of 11th minute, in one sand glass we have completed 11minutes and 4 minutes in other.Now reverse the sand glass that completed 4 minutes and it takes 4 minutes to empty out the upper portion

As a whole one sand glass counts 11 minutes and the other counts 4 minutes. That sums up to 15 minutes...

1. Start both the 7 minute hour glass & 11 minute hour glass.

ReplyDelete2. Wait till the 7 minute hour glass times out. Time is 7 minute!

3. Restart the 7 minute hour glass. At this time 11 minute hour glass will have 4 minutes left to time out.

4. As soon as 11 minute glass times out invert the 7 minute hour glass. Total time now is 11 minutes.

5. After inverting 7 minute hour glass, it will now have 4 minutes left for time out.

6. After these 4 minutes times out, the total time is 15 minutes.