July ’23: The Brain Teasers (and Bonuses) below (from Summer ’19) will be re-available through September ’23 Answers will be shared in early October.
NOTE: Newest BTs in red, Bonuses in blue, comments in green, updates in purple.
- A man is walking his three dogs when he meets his brother who is walking his two dogs. How many feet are there in total when they meet?
- What do female elephants have that no other animals have?
- Sammy was a real bookworm who spent all his time in the local library. In just one month he worked his way through three volumes of an encyclopedia, and two volumes of a dictionary, yet he could not remember one word that they contained. Why was that?
- (Partial repeat) T or F? A) If the sum of two numbers is even, then both numbers are even. B) If the product of two numbers is even, then both numbers are even. C) A number with 5 factors is always bigger than a number with 4 factors.
- Many of you are familiar with my love of palindromes, especially when they appear on the odometer. Very recently, I ran into an interesting situation. I saw TWO palindromes two miles apart, and then realized that I wouldn’t see another one for 1100 miles!! I just saw it last week! Given those circumstances, what are the three palindromes?
- What makes the number 8,549,176,320 unique? Hint 1: Don’t look for anything terribly ‘mathematical’ here. Hint 2: The answer might be different in other countries.
- (Via Cherry Hinderberger). In the classic “Twelve Days of Christmas” song (swans, geese, pear tree, etc.) how many total gifts are given over the twelve days?
- A club containing 10 members decides to elect a President and a VP. a) How many slates of officers are possible? b) How does that number change if they also elect a Sec/Treas (one office)?
- Let’s suppose your heart beats 70 times/minute. How many times will it beat in August?
- The average (mean) of 3 tests is 74. What score is required on the 4th test to raise the test average to 78?
- Find the sum of the reciprocals of whole-number factors of 24. (Remember ‘reciprocals’? For example, the reciprocal of 7 is 1/7.)
- In any given leap year, what date marks the 2/3 point of the year?
- Miss Korn collected coins and referred to her collections with interesting nicknames. Her penny collection she called Cu, and her nickels collection, she called Ni. What do you think she called her collection of silver dollars?
- In a recent column (Twain, Teams, and Turf) we referred to five different entities (schools, parents, religion, society, and government) involved in our broader education and looked more closely at at the four (4) pairs of those teams involving schools. Out of those 5 entities, however, how many total pairs (teams 0f 2) are there?
- I open my mathematics book, and the page numbers that face me have a product of 1806. What are the two page numbers?
- The sum of the ages of Al and Bill is 25. The sum of the ages of Al and Carl is 20. The sum of the ages of Bill and Carl is 31. Who is the oldest of the three and how old is he?
- A recent Crossword Puzzle indirectly led to this Brain Teaser: What do the following phrases all have in common: “Goldwyn Pictures”, “folding brackets”, “tumbledown shack”, “crazy stupid love”, and “rhyming couplets”
- See Pic below. (The two figures are 170 and 130 cm, left to right.)
BONUS 1: I have seven billiard balls, one of which weighs less than the other six. Otherwise, they all look exactly the same. How can I identify the one that weighs less on a balance scale, using that scale no more than two times?
BONUS 2: Exactly the same situation as Bonus 1, only now you have A) 8, and B) 9 billiard balls. Can you do either/both parts?
BONUS 3: See B1 and B2 above, with same conditions except that you now get THREE weighings. Is it possible to achieve the same goal if there are 18 billiard balls? Make your argument either way.(Demonstrate for, or argue against.)
BONUS 4: See #14 above. Of the five entities there, how many TOTAL teams of any number (pairs and teams of 3, 4, or 5) are there?
CREATIVITY BONUS A: Make as long a sentence as you can (at least 5 words?) where every word starts with the same letter. (LOTS of ‘right’ answers, of course!!)
CREATIVITY BONUS B: The Herman cartoon below has had the caption (temporarily) removed. Submit your own caption and get us laughing!! (Later we may decide we like some of these submissions better than the original!) (added July ’23: Indeed, I’m not sure I can re-find the original caption. :-))
CREATIVITY BONUS C: Submit a good Creativity Bonus idea for this section!!
1..24 legs
2..baby elephants
4..A..False (3+1=4)
B..False (2×3=6))
C..False (12 whose 5 factors are 2,3,4,6,and 12, is NOT bigger than 18 whose 4 factors are 2,4,8, and 16)
1. 24 feet. All mammals with legs have feet assuming no amputations. 5 dogs (20) and 2 humans (4).
2. Baby elephants, elephant milk, elephant ova
3. Sammy is a worm and is illiterate.
4.
A. False (3 + 7 = 10)
B. True
C. False (1X2X3X4X5 = 120)
(1X2X3X61 = 186)
Bonus A. Amos absolutely admires Amelia, Amy, Ashley, and Andy as amazing assessors, accountants, academic, and advocate against abusive asses.
Bonus A. Zillionaire Zachary Zalman zealously zips zazzy zeppelin zigzag zippers zestily.
Bonus A.
Xenophylic Xzavier Xenthopoulos xeroxes xanthic xenomorphic xenosarous x-rays.
1. 24 legs
2. Baby elephants
3. A REAL bookworm literally ate his way through the books.
4.F; F; F
6. All digits are used exactly once
Creativity Bonus A
Handsome, helpful Henry has handily helped his helper, Henrietta, haunt her husband’s house; henceforth he heartily hates hauntings!
18 words
Why was Wacky Waldo whining wistfully when wierd wanda watched wilber wallowing with witty women woozy with warm watermelon wine, while whimsically whistling Winter Wonderland. (that is all I got)
#5
Thought I had it with 9,999 and two miles later 10,001. But that would only take 100 miles to get to the next-10,101🤪
1. 4 feet, the rest are paws.
2. Baby elephants
3. Sammy ate them because he’s a real worm.
4. A. False B.True C. False
Bonus 1. Weigh 3 on each side. If they are equal, then the one left is the lighter one. If one side of the scale is lighter then weigh 2 of those. If they are the same then it is the one left. If one is lighter then it is that one. If you are using 8, weigh 3 on each side and see if they weigh the same. If they do, weigh the remaining 2 to find the lighter one. If not, weigh 2 of the ones that is on the lighter side like in the first one. If you have 9, do the same thing as before. Weigh 3 on each side and if they weigh the same, weigh two of the remaining three to see which one is lighter.
Attention Subscribers: As you know, I normally don’t share/post/’approve’ Comments that appear as BT answers before the submission deadline.
But on Creativity Bonus A, that doesn’t appear to be a problem, since there are SO MANY ‘right answers’ and perhaps these will inspire you to try your own!! So I’ll make exceptions for those* (and perhaps other Creativity Bonuses?) –
*as long as they come in separately and not with other BT answers.
Alexis Avis’ submission:
Handsome, helpful Henry has handily helped his helper, Henrietta, haunt her husband’s house; henceforth he heartily hates hauntings!
Jim Waterman’s 3rd submission:
Amos absolutely admires Amelia, Amy, Ashley, and Andy as amazing assessors, accountants, academic, and advocate against abusive asses.
Earlier Submissions (Mar-May):
Rita Barger’s submission: Arthur, Ann, Alex, Avery, and Arabella are all alert, ambitious, ambidextrous, alarmed, adopted actors actively attracting albatrosses and arresting aardvarks.
Amy Ragsdale’s submission: Many mischievous monkeys merrily made myriad mango marmalade Monday morning.
[NOTE: Post partially edited to delete solution submission. LNC] . . . the two guys have four feet and the dogs have paws, which gives me pause. Why is a cat like a comma. Because one has a pause at the end of a clause and the other has claws at the end of its paws. And that long number has all the numbers from 1 to 9. So why are owls smarter than chickens? Well you never saw Kentucky Fried Owls.
Hi Dan – always fun to hear from you!! I like the Kentucky Fried Owls! I may have to steal that one. 🙂
Larry
28 feet.?
Larry,
I saw an article about a woman who delivered a baby on 7-11 Day at 7:11 PM and the baby weighed 7 lbs 11 ounces.
Search the news for 7 11 Day birth 7 11 PM 7 pounds 11 ounces
Jdw
Thanks, Jim!! I’ll see what I can find. As you know, that’s my kind of statistic! 🙂
BT#7…364 gifts.
#9…3,124,800 beats.
#10…score of 90.
#11…sum of reciprocals =
2 1/2.
#12…August 31st.
BT#6…the digits are in alhabetically in order.
#13…Ag
BT#6…the digits are alphabetically in order.
#13..Ag
1. If you consider the dogs as having feet, there are 24 feet. If you consider the dogs as having paws, there are 4 feet.
2. They have baby elephants.
3. Sammy was literally a worm (eating through books).
4. A) false. B) false. c) false {16 has 5 factors and 35 has 4 factors}
6. It shows all the digits zero through nine in order ALPHABETICALLY.
7. 364 total gifts (I have used this same question as a bonus on a 1st semester final for many years.)
8. A) 10×9=90 B) 10x9x8=720
9. 3,124,800 beats in August
10. score 90 on 4th test
11. 2 1/2
12. the 244th day, Aug. 31st
13. Ag
14. 10 pairs
Bonus 1: Place 2 balls on each side of scale. If the scale IS balanced, take off those 4 balls and put one of the remaining 3 on each side of the scale, which will show that either one of those balls is lighter, or the last ball (not weighed) is lighter.
If the scale IS NOT balanced, take the 2 balls off the heavier side and weigh the 2 balls on the lighter side separately to find which one is lighter.
Bonus 2: A) Yes, it is possible with 8 balls B) Yes, it is possible with 9 balls
Bonus 4: 10+10+5+1= 26 total teams of any number.
BT#15…Pages 42 and 43.
15. pages 42 & 43
16. Bill is the oldest, age 18
Bonus 3: Since you are allowed 3 weighings, yes it is possible to determine which ball weighs less. Begin by placing 9 balls on each side of the scale to determine which group of balls contains the lighter one. Then follow the same process that was used in Bonus 2(B) – place 3 balls on each side of the scale. Either the scale WILL balance (in which case you weigh 2 of the remaining 3 balls not on the scale to determine the lighter one), or the scale WON’T balance ( in which case you choose 2 of the 3 balls on the lighter side of the scale to weigh and determine it is either one of those 2 or the one that is not on the scale.)