Summary, Solvers, and Solutions: Nov/Dec ’18 BTs

Sep/Oct ’18 Brain Teasers – SUMMARY

REMINDER: Answers in red.  Solvers (submitted/correct) in blue. (Forgive any omissions, but feel free to inform.) Comments in green. For further elaboration, please feel free to ask! 

1.  Check out this Krazy Pic from the 10/29 mailing.  Why do we know this picture probably came from Great Britain, say, rather than the US? (I just noticed there is ALSO another subtle semi-clue – anyone catch it?)  The most likely clue is the British spelling of the word ‘colour’.  (The other subtle clue is the character on the sign is Andy Capp, a British cartoon character. [The strip was popular in US, too.]  Rita Barger, Kathy Gordon, Jennifer Steele.
2.  Check out this riddle.  Interesting, and ‘outside the box’.  (I’d probably change the question to ‘of the four names here, which is most likely . . .’, but hey.) The lady’s six children contain the first six notes of the musical scale: Do, Re, . . .  So following that pattern, the likely choice is Ti(tus). Rita Barger, Frank Green.
3.  J.J.J. Smith has an 85 average on his four tests in Calculus.  The final is the same weight as each test – all are 100 points.  What will he need to score on the final, to bring his grade up to an A (90 average)? It can’t be done (with 100 point tests.)  [He has 340 points now.  For a 90 average on 5 tests, he’d need a total of 450, or 110 more points.] This is a classic example of the adage “you can’t average averages”.  Rita Barger, Kathy Gordon.
4. If you write down every whole number (integer) between 500 and 700, how many times will you write the digit 6?  140 times. Rita Barger, Jennifer Steele.
5.  I’m Rodney and I live on a farm.  With me are 4 other dogs named Brownie, Spot, Fido, and Blackie. There is a fifth dog – what is it’s name?  Rodney.  🙂 Rita Barger, Kathy Gordon, Jennifer Steele Frank Green.
6.  Ralph went for 5 days without sleep. (He felt and acted perfectly normal.  Why is that? He slept fine at night. Rita Barger, Kathy Gordon, Frank Green.
7.  How is your mother’s sister’s brother in law related to you? More than likely, your father.  (“Uncle” is also possible in some circumstances, and credit was given for that.) Rita Barger, Kathy Gordon, Jennifer Steele.
8.  Always, sometimes, or never?  A)  A right triangle has an acute angle. Always.  B) A right triangle has an obtuse angle. Never. Rita Barger, Kathy Gordon, Jennifer Steele, Frank Green.
9.  Always, sometimes, or never:  A)  The radius of a circle is longer than the diameter. Never.  B)  A triangle with 2 equal sides is equilateral.  Sometimes. Rita Barger, Kathy Gordon, Frank Green.
10. If p is a prime and  2p – 1 is also prime, then 2p – 1 is called a Mersenne Prime.  Find the three smallest Mersenne primes. 3, 7, 31.  (So much more that could be said here, but . . .) Rita Barger, Kathy Gordon.
11.  I am divisible by 5 and I am odd.  I have less than 4 digits, but am greater than 12 x 12.  The sum of my digits is a square and their product is 15.  What number am I?  315. Rita Barger, Kathy Gordon, Frank Green
12.  Find the area and perimeter of a right triangle with legs of 4 & 5. (Apologies all around.  I meant to say legs of 3 & 4, making it a classic 3,4,5 rt. triangle, and therefore a much easier problem. My brain and my fingers were not in sync, apparently.)  Area = 10 (sq units), Perimeter = 9 + SQRT(41). Rita Barger (with partial credit to Kathy Gordon [one part correct, slippery error on other], and Frank Green [who solved the problem I intended. 🙂 ] )