BrainDen.com - Brain Teasers

# All Activity

1. Today

My try at it
3. ## I'm not an outlaw's ghost

Getting warm, but still looking for something that's hidden while out in the open.
4. ## Square Free

So ... 3x best answers from me?

I'll say:
6. ## I'm not an outlaw's ghost

Hole In The Wall Gang....
7. ## 20 RIDDLES TO TEST YOUR MATH, IQ AND THINKING SKILLS.

. What is the value of x If 1/2, 2/3, 3/4, 4/5, 5/6, 6/7, 7/8, 8/9, 9/10 then x/1000? x = 500,000 2. If 4 and 2= 26, 8 and 1 = 79 and 6 and 5 = 111. Then, what is 7and3?...410 3. What 3 positive numbers give the same result when multiplied and added together? 2 mis interpreted the Q 1,2,3 is correct 4. What number do you get when you multiply all of the numbers on a telephone's number pad? zero 5. Here is a light switch. Note the order of the positions. If the light is now at medium and it is switched 3922 times what will be the position of the switch? medium I assumed in the absence of additional info there were 3 positions . i.e low , med , high. any even number of flips will put the sw back on med 6. Can you arrange four nines to make it equal to 100. 99 9/9 8. If 1/2 of 5 is 3, then what is 1/3 of 10? 3.67 I envisioned 1/2 of 5 = 2 1/2 + 1/2 = 3; therefore 1/3 of 10 = 3.33 + 1/3 =3.367 9. 100 students entered college. 55 of them chose music. 44 of them chose sports. 20 of them chose both. How many of them chose neither music nor sports? 21 10. Four friends are going to a concert. When they arrive, there are only five seats together left in the theater. The manager will let all four friends in for free if one of them can tell her how many different seating arrangements are possible for four people with five empty seats. 120 5 seats taken 4 at a time 5 ! All four are let in free. Could you have given the correct answer? 120 5 seats taken 4 at a time 5 ! 12. At six o’clock the wall clock struck 6 times. Checking with my watch, I noticed that the time between the first and last strokes was 30 seconds. How long will the clock take to strike 12 at midnight? 5 hrs 59 1/2 minutes 13. There are several books on a bookshelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf? 9 14. John has been hired to paint the numbers 1 through 100 on 100 apartments. my bad 20 How many times he has to paint 8? 20 15. You have two books. One of them is upside-down and the other is rotated so the top of the book is facing you. What is the sum of the first page in each book? 1 +1 16. There is a certain club which is for men only. There are 600 men who belong to this club and 5% of these men wear one earring. Of the other 95% membership, half wear two earrings and the other half wear none. How many earrings are being worn in this club? 600 17. Does a pound of gold or a pound of feathers weight more? feathers 18. There is a chain nailed to the wall. The chain is 10 feet long and the center of the chain dips down 5 feet from where each side of the chain is nailed to the wall. How far are the 2 ends of chain from each other? on the same nail 19.Little Johnny is walking home. He has \$300 he has to bring home to his mom. While he is walking a man stops him and gives him a chance to double his money. The man says "I'll give you \$600 if you can roll 1 die and get a 4 or above, you can roll 2 dice and get a 5 or 6 on at least one of them, or you can roll 3 dice and get a 6 on at least on die. If you don't I get your \$300." What does Johnny do to have the best chance of getting home with the money? keep on walking 20. If you have 6 women and 2 friends, how many women do each of your friends get if the friends are two of the 6 women;i.e. women themselves , then each is entitled to herself, or one each/ If the two friends are male then no women.
8. ## 20 RIDDLES TO TEST YOUR MATH, IQ AND THINKING SKILLS.

. What is the value of x If 1/2, 2/3, 3/4, 4/5, 5/6, 6/7, 7/8, 8/9, 9/10 then x/1000? x = 500,000 2. If 4 and 2= 26, 8 and 1 = 79 and 6 and 5 = 111. Then, what is 7and3?...410 3. What 3 positive numbers give the same result when multiplied and added together? 2 4. What number do you get when you multiply all of the numbers on a telephone's number pad? zero 5. Here is a light switch. Note the order of the positions. If the light is now at medium and it is switched 3922 times what will be the position of the switch? medium 6. Can you arrange four nines to make it equal to 100. 99 9/9 8. If 1/2 of 5 is 3, then what is 1/3 of 10? 3.67 9. 100 students entered college. 55 of them chose music. 44 of them chose sports. 20 of them chose both. How many of them chose neither music nor sports? 21 10. Four friends are going to a concert. When they arrive, there are only five seats together left in the theater. The manager will let all four friends in for free if one of them can tell her how many different seating arrangements are possible for four people with five empty seats. 240 All four are let in free. Could you have given the correct answer? 240 12. At six o’clock the wall clock struck 6 times. Checking with my watch, I noticed that the time between the first and last strokes was 30 seconds. How long will the clock take to strike 12 at midnight? 5 hrs 59 1/2 minutes 13. There are several books on a bookshelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf? 9 14. John has been hired to paint the numbers 1 through 100 on 100 apartments. 11 How many times he has to paint 8? 11 15. You have two books. One of them is upside-down and the other is rotated so the top of the book is facing you. What is the sum of the first page in each book? 1 +1 16. There is a certain club which is for men only. There are 600 men who belong to this club and 5% of these men wear one earring. Of the other 95% membership, half wear two earrings and the other half wear none. How many earrings are being worn in this club? 600 17. Does a pound of gold or a pound of feathers weight more? feathers 18. There is a chain nailed to the wall. The chain is 10 feet long and the center of the chain dips down 5 feet from where each side of the chain is nailed to the wall. How far are the 2 ends of chain from each other? on the same nail 19.Little Johnny is walking home. He has \$300 he has to bring home to his mom. While he is walking a man stops him and gives him a chance to double his money. The man says "I'll give you \$600 if you can roll 1 die and get a 4 or above, you can roll 2 dice and get a 5 or 6 on at least one of them, or you can roll 3 dice and get a 6 on at least on die. If you don't I get your \$300." What does Johnny do to have the best chance of getting home with the money? keep on walking 20. If you have 6 women and 2 friends, how many women do each of your friends get if the friends are two of the 6 women;i.e. women themselves , then each is entitled to herself, or one each/ If the two friends are male then no women.
9. Yesterday
10. ## I'm not an outlaw's ghost

I'm not a picture frame. Tough in my mind to interpret it as having been found only by those now dead. Also not a skydiver. I'm something more commonly known for grabbing everything. Not an excavator. I don't envision him hanging and then being hung by the same "man". And also not a shovel for similar reasoning.
11. ## I'm not an outlaw's ghost

Sorry, no spoiler with phone. I go shovel.
12. ## A Convicted Riddle

Well done guys. Thought you'd get a grin out of that.

if not an
14. ## A Convicted Riddle

trying to chime in here before Wilson too late. and of course his is excellent. rats!

16. ## A Convicted Riddle

I'm kicked around both night and day By fellow inmate, locked away. The yarns of hope for him I spin Are simple tricks, his out is in. And yet my cellmate doesn't pout; He still endeavors to get out.

18. ## 20 RIDDLES TO TEST YOUR MATH, IQ AND THINKING SKILLS.

Didn't watch the video - Will take too much data (for me)! Please show us the answers after everyone has had a go at them!

20. ## 20 RIDDLES TO TEST YOUR MATH, IQ AND THINKING SKILLS.

Thank you so much, I really appreciate that you point out this, I will fix this in my next video. And overall I agree with most of your opinions and I will do my best. Update. 5. Image attached with this reply. 7. Divide 110 into two parts so that one will be 150 percent of the other. What are the 2 numbers? 11. The number of bacteria in a large sealed jar doubles every minute. The bacteria will take an hour to fill the jar. When will the jar be half full? 20. I added just for fun! And Honestly, I apologize for the errors I made in this thread, Sorry for ruining your fun and Thank you all for being so nice. This is a great forum. I love you all.
21. ## Square Free

@rocdocmac Your 2nd solution is the only position I thought possible. plasmid almost have it if he made adjustment of "d7" Salutes for your 2 more solutions!
22. ## 20 RIDDLES TO TEST YOUR MATH, IQ AND THINKING SKILLS.

I watched the video, and overall liked it. Since you asked for feedback: with the video format, I think I would prefer to see the question and be told to pause to have time to think of the answer before it appears instead of having a set amount of time for each question, since with at least some of them you either know it or you don't right off the bat. As it is, I got a little annoyed waiting a minute for the answer if I already knew it. The other main comment is something DejMar sort of alluded to, that there are potentially multiple answers that would make sense for some of the riddles. In particular the second one, I also interpreted it as most likely being a gotcha where each number in the sequence is (n)/(n+1), so the final term x/1000 comes after 9/10 and should equal 10/11, meaning x = 10 x 1000 / 11. Only after realizing that it wouldn't be an integer did I decide that it probably wasn't what you intended to ask, so the answer should be the other thing I had in mind and be x = 999. With the light switch, when I saw it here I thought there must be three positions with something like "off" going to "medium", "medium" going either to "off" or to "high", and "high" going only to "medium" so there would be a unique answer -- after any even number of flips the switch must be back at "medium" -- whereas with the youtube version if you change directions during flipping you could either end up at the original position or 180 degrees away. For the question of painting 8s, I could have interpreted a couple of ways: you could argue that he would only paint 8 once (if it's referring to house number 8, or just the number 8 and not other numbers that happen to have 8 as a digit), that he would paint it 20 times (if you mean the total number of digits that are 8), or maybe even 19 times (if you mean the total number of houses with any 8 on them, although that's a less likely interpretation). DejMar commented on the ambiguity of whether the question with Little Johnny is talking about making it home with the original \$300 dollars or the money that the man is offering, but I suppose that ambiguity needs to be present or else it wouldn't be much of a riddle. And the last question seems like it might be a bit offensive if asked to a woman. It might not be possible to make the questions entirely unambiguous, especially the question about Little Johnny since the ambiguity is what makes it a riddle in the first place, but sometimes simple things like saying "how many times does he have to paint the digit 8" can help make it unambiguous. In general, I would say to check for (and ask other people to check for) unintended ways that the questions might be interpreted.
23. ## I'm not an outlaw's ghost

Not an escalator. If I remember correctly the track record here has been that people's guesses about the difficulty of their own riddles ended up having little to no correlation with how tough they were for everyone else, so who knows.