Measuring 9 minutes from 2-hour glasses Puzzle
Measuring 9 minutes from 2-hour glasses Puzzle
Using only a Four-minute hourglass and a seven-minute hourglass, How will you measure exactly nine minutes?
Restriction:- The process should not take longer than nine minutes.
Solution
We measure 7 Minute from One Hourglass.
We reverse it at 7th minute
And, 4+4=8 Minutes from Second Hourglass – 8 Minutes
8 (from 1) – 7 (From 2) = 1 Minute – 1 Minutes
TOTAL = 9 MINUTES
4 Minutes – The four-minute glass runs out. Flip the four-minute glass.
7 Minutes – The seven-minute glass runs out. Flip the seven-minute glass.
8 Minutes – The four-minute glass runs out; the seven-minute glass has been running for one minute. Flip the seven-minute glass.
9 Minutes – The seven-minute glass runs out.
Detailed Solution
0 Minutes – Start both hourglass at the same time.
4 Minutes – The four minute glass runs out. Flip the four minute glass.
7 Minutes – The seven minute glass runs out. Flip the seven minute glass.
8 Minutes – The four-minute glass runs out; the seven-minute glass has been running for one minute. Flip the seven-minute glass.
0 Minutes – Start both hourglass at the same time.
Prime Course Trailer
Related Banners
Get PrepInsta Prime & get Access to all 200+ courses offered by PrepInsta in One Subscription
Get over 200+ course One Subscription
Courses like AI/ML, Cloud Computing, Ethical Hacking, C, C++, Java, Python, DSA (All Languages), Competitive Coding (All Languages), TCS, Infosys, Wipro, Amazon, DBMS, SQL and others
- Crossing the Bridge Puzzle Answer
- Death & Marbles Puzzle Answer
- Airplane Seat Puzzle Answer
- 2 Eggs & 100 Floors Puzzle Answer
- Bank Cashier Puzzle Answer
- Calendar Cube Puzzle Answer
- Ants & Triangle Puzzle Answer
- Bulb in a Circle Puzzle Answer
- Camel & Bananas Puzzle Answer
- King & Wine Puzzle Answer
- Sum & Product Puzzle Answer
- Heaven or Hell Puzzle Answer
- 3 Mislablled Jars Puzzle Answer
Login/Signup to comment