Recent Comments
Senthil Kumar VS on Solution to Puzzle #200: Achie… Alok Goyal on Puzzle #200: Achieve your… Vishal Poddar on Puzzle #200: Achieve your… Alok Goyal on Puzzle #200: Achieve your… Abdul on Puzzle #200: Achieve your…
Tag Archives: numbers puzzle
Puzzle #176: Outsmart Your Teacher
This is a relatively simple puzzle from fivethirtyeight.com, a site from which I have posted many puzzles in the past. Variations of such puzzles have been posted in the past. I would encourage parents to try this with their children. … Continue reading
Solution to Puzzle #53: Make a Century
Addendum to the answer…Shruti Mittal sent 6 more correct asnwers – Well done Shruti! (-1*2)-3-4-5+6*7+8*9=100 1+(2*3)+(4*5)+(-6+7)+(8*9) 1*(2+3)*4*5*(6-7)*(8-9) 1*(2+3)*Sqrt(4)*5*{-[(6-7)+(CubeRoot(8)-Sqrt(9)]} … Continue reading
Puzzle #53: Make a Century!
Thanks to Alok Mittal for sharing this cute problem to which there are many answers…limited only by your creativity! Insert mathematical signs between digits 1,2,3,4,5,6,7,8,9 to make an expression that equals 100. The digits must remain in the same sequence. … Continue reading
Puzzle #50: Cat and Mouse Tale
This is a nice puzzle for children that I picked from the book “Moscow Puzzles” (Puzzle #88). See the figure below: Cat has decided to take a nap. He dreams he is encircled by 13 mice: 12 gray and 1 … Continue reading
Solution to Puzzle #49: The Absent Minded Bank Clerk
I surprisingly got much fewer responses than I expected, and in hindsight, the “two minute” qualifier probably scared people! Congratulations to Muskaan Mittal, a brilliant 9 year old, in being the first one to send the answer. Girish Tutakne and … Continue reading
Puzzle #49: Two Minute Test – The Absent Minded Bank Clerk
This is a simple gem I found again in a Martin Gardner book – More Mathematical Puzzles and Diversions, Chapter 14, Puzzle #8. I urge all the adults who try this puzzle to put this as a 2-minute challenge for … Continue reading
Solution to Puzzle #47: Each Digit Only Once
First of all, need to thank Ankita and Mohit again for the puzzle…wonderful one. Got lots and lots of answers, and as it turns out, there are quite a few answers. Proper treatment of the answer requires a video but … Continue reading
Solution to Puzzle #45: Prime Numbers
Apologies for not posting the solution last week, was traveling out of town on vacation. Also need to thank everyone for a “bumper response” to the puzzle. I got more answers to this puzzle than any other puzzle in the … Continue reading
Solution to Puzzle #37: Four 9’s and 100
I surprisingly got fewer answers than I expected. The most noteworthy response was from Ruchir Godura, who rattled a whole set of possibilities. I cannot prove that this is the exhaustive list, but here are the ones I have come … Continue reading
Puzzle #26: Get to the number 14
This is a relatively simple arithmetic puzzle, that I found interesting to do with my 9 year old. I picked this up from Mathematical Circles. Here is the puzzle: You begin with the number 458. You are only allowed two … Continue reading
