Tuesday, December 30, 2008
A Holiday Riddle: What do you call solving an equation twice on Jan 1st?
The first 5 who email me with the correct answer to this silly riddle will receive international acclaim!
Please do not post your answer as a comment!
Email me using the link below the post or at dmarain at geeeeemailllll dottt kom!
Also, include the following info:
(1) Your full name
(2) Your connection to math (student, educator, math enthusiast, etc.)
(3) How you found MathNotations (or if you're a long-time visitor)
(4) If you have your own silly math riddle for the occasion, pls share it!
Posted by Dave Marain at 7:11 AM 0 comments
Labels: riddle
Friday, June 13, 2008
A Math Riddle that gets better with 'Age'!
[Don't forget the Mystery Math Anagram for this month. Only two correct replies have been received thus far. I will announce the winners in a few days.]
Have you been wondering where the math challenges have gone on this blog? Here's one that I came across while reading David Baldacci's recent best seller, Simple Genius, just your usual tale of the dark world of mathematicians, codes and spies. Gee, math has become such an integral part of novels, TV shows and movies over the past few years, our students are going to think the life of a mathematician is really cool and exciting (which, as we all know, it is!).
Anyway, here is a paraphrasing of the problem (as long as I'm not copying the problem verbatim, the publisher granted me permission to discuss this):
Alex is as many months old as his grandpa is in years and about as many days old as his dad is in weeks. If the sum of their 3 ages is 140, how old is each?
Hint: This is a wonderful problem demonstrating the power of ratios. If you can solve it less than 20 seconds, then you're either an honorary member of Mensa or you could be the subject of Baldacci's next book!
Comments
(1) Like all riddles, the wording is somewhat convoluted and the mathematical assumptions are not explicitly stated. But that's part of the intrigue here. I will say that one needs to assume the ages are integers, but that's about it.
(2) In the novel, the problem is posed to a young mathematical prodigy named Viggie. While another mathematician in the room takes some time to solve it algebraically, Viggie comes up with the solution mentally in a few seconds. Can you!
(3) You may want to give this to middle school students, although the wording might frustrate them. You could demonstrate the idea with a concrete example or make it into a simpler problem:
Let's say that Alex is 96 months old, then his grandpa would be 96 years old. Now ask them to determine how old Alex's dad would be. This may be challenging enough...
(4) I'm naturally wondering what the source of this problem is. If anyone out there recognizes it, let us know its source!
Posted by Dave Marain at 6:03 AM 9 comments
Labels: age problem, math challenge, ratios, riddle