BRAIN-TEASERS 02

Brain-Teaser 02 | LCM, Measuring Rod & Milk Puzzle | Key To Enjoy Learning Maths

๐Ÿง  BRAIN-TEASER 02
LCM, Measuring Rod & Milk Puzzle

๐Ÿ”ข LCM Puzzle: A boy was asked to find the LCM of 3, 5, 12 and another number. But while calculating, he wrote 21 instead of 12 and yet came with the correct answer. What could be the fourth number?
✅ Answer: 28
๐Ÿ“– Explanation: LCM(3,5,12)=60, LCM(3,5,21)=105. For both to be equal, N must contain 2²×7=28. LCM(3,5,12,28)=LCM(3,5,21,28)=420.
๐Ÿ“ Measuring Rod Puzzle: Five pieces of cloth: 15 m, 21 m, 36 m, 42 m, 48 m. All measurable in whole units. Largest possible rod length?
✅ Answer: 3 metres
๐Ÿ“– Explanation: GCD(15,21,36,42,48) = 3. The rod must divide all lengths exactly.
๐Ÿฅ› Milk Measuring Puzzle: 10L, 7L, 3L cans. No markings. Measure exactly 5 litres.
✅ Answer: Yes, 5 litres can be measured
๐Ÿ“– Method: Fill 9L can, pour to 5L → 4L left. Empty 5L, pour 4L into 5L. Fill 9L again, pour to 5L (needs 1L) → 9L left with 8L. Empty 5L, pour 8L into 5L → 3L left in 9L can. ✅
๐Ÿ” Two-digit number puzzle: When added to 27 gives its reverse. Find the numbers.
✅ Answer: 14, 25, 36, 47, 58, 69
๐Ÿ“– Explanation: 10a+b+27=10b+a → 9a-9b=-27 → b=a+3. a=1 to 6 gives the numbers.

๐Ÿ“˜ WATCH IT ON FLIPBOOK

๐Ÿ”— CLICK HERE FOR INTERACTIVE FLIPBOOK
๐ŸŽ‰ Play & Learn with your Friends Kutties! ๐Ÿ‘
All the best!
Thank You ๐Ÿ™๐Ÿป

No comments:

Post a Comment

class9-ch7-solutions Ganita Manjari

Ganita Manjari – Class 9 Mathematics Key to Enjoy Learning Maths · keytoenjoylearningmaths.blogspot.com · Part 1 & Part 2 Part 1 P...