NOTE: Newest BTs in red, Bonuses in blue, comments in green, updates in purple.
- Consider the complement of any acute angle and the supplement of any obtuse angle. Is one of those always bigger (which one?) or might they vary?
- Consider any positive rational number and that number’s square root. . Is one of those always bigger (which one?) or might they vary?
- Which two whole numbers with a sum of 50 will give the largest product?
- Two (distinct) numbers are chosen at random from the set (2,3,5,7) and multiplied together. How many of the possible products are odd?
- Find the product: (1 – 1/2) * (1 – 1/3) * (1 – 1/4) * . . . * (1 – 1/10)
- Find the product of all the even integers between -25 and 25.
- If the radius of a circle is tripled, how much is the area of the circle increased?
- In a strange house, there are 6 rugs and on each rug sits 6 six-legged tables. On each table, there are 6 six-legged creatures. What is the total number of creature legs in this silly story?
- The mean of all the primes between 40 and 50 is subtracted from the median of the same primes. To two decimal places, what is the absolute value of the answer?
- HELP!! I thought certain I had added at least one BONUS to the Brain Teasers this time around, but either I never did, or it has disappeared in various revisions. CAN YOU HELP ME? Help me solve this riddle (send me the Bonus or let me know it was never there) – and receive credit for this Brain Teaser!!
- Have you seen the US Post Office’s new stamp??! Check in out here. Imagine – a puzzle on a stamp!! Decipher the message, and get your BT credit! (you can look it up of course, but it’ll be more fun if you don’t.)
I don’t buy this ‘Only for Genius’ stuff. This one’s not hard – what goes where the ? is??- The number 555,555 can be expressed as the product of two 3-digit numbers. What is the smaller of those two?
- Two standard dice are rolled. What’s the probability (in fraction form) that the sum of the two numbers is prime?