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Math riddles

Numbers are something we learn as children. These are important since many of the world’s questions can actually answered with math. Math is very important in our world, without it we would not have such a great society we have. For all those who love math, I would like to present these amazing math riddles. What are you waiting for, go ahead and try to solve them.

Dan deals himself and his friend Mark some cards from a deck of cards (not the same amount). If Mark gives Dan some cards Dan will have 4 times as many cards as Mark If Dan gives Mark the same number of cards he will have 3 times as many cards as Mark.
How many cards does each man have and how many cards do they trade?
Dan has 31 cards, Mark has 9, and they trade 1 card.
What did one math book say to the other?
Don’t bother me I’ve got my own problems!
A merchant can place 8 large boxes or 10 small boxes into a carton for shipping. In one shipment, he sent a total of 96 boxes. If there are more large boxes than small boxes, how many cartons did he ship?
11 cartons total
7 large boxes (7 * 8 = 56 boxes)
4 small boxes (4 10 = 40 boxes
11 total cartons and 96 boxes.

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 books.
What is the smallest three digit palindrome divisible by 18? Can you solve this without a brute force examination of possibilities?
The answer for this math riddle is 252.
If you have 30 white socks, 22 black socks, and 14 blue socks scattered across the floor in the dark, how many would you have to grab to get a matching pair?
4. Once you grab 4 you will definitely have 2 of the same color.
Five pirates are parting ways after finding a treasure of 100 pieces of gold. The pirates decide to split it based on a vote. Each pirate, from oldest to youngest, gets to propose a plan on how to split the gold.
If at least 50 percent of the other remaining pirates agree on the plan, that is how they will split the gold. If less than 50 percent of the pirates agree, the pirate who came up with the plan will be thrown overboard. Each pirate is smart, greedy, and wants to throw as many others overboard as possible without reducing the amount of gold they get.
What plan can the first (oldest) pirate propose to live and get as much gold as possible?
He can propose a plan that he gets 98 pieces of gold, the 3rd pirate gets 1 piece, and the 5th pirate gets 1 as well.
If there were just 2 pirates the younger pirate would definitely deny the plan so he could get all of the gold.
If there were 3 pirates the first pirate can offer the second pirate 1 piece of gold and take the rest himself because the second pirate wouldn’t get anything if he has to propose a plan himself.
If there were 4 pirates the first pirate could take 99 for himself and offer 1 to the youngest pirate. They would both agree. If the youngest disagrees then he won’t get any gold in the next plan.
So when there are 5 pirates it is in the interest of the 3rd and 5th pirate to accept 1 piece, because if they don’t they won’t get anything in the next plan.

Can you solve all the Math riddles

Using only addition, how can you add eight 8's to get the number 1,000?
888 +88 +8 +8 +8 =1,000
Does a ton of feathers or a ton of bricks weigh more?
They both weigh a ton.
As I was going to St. Ives,
I met a man with seven wives,
Kits, cats, sacks, and wives,
How many were there going to St. Ives?
The answer is 1. The only person that is assumed to be going to St. Ives is the narrator. But the following answers can be found if looking at the question in other ambiguous ways: 2802, 2800, 0, 2, 2753, 7, and 9.
What 3 positive numbers give the same result when multiplied and added together?
1, 2, and 3.
There are 100 passengers boarding a 100 passenger airplane. When passenger 1 gets onto the plane, he is dissoriented, so he randomly picks a seat. Each of the remaining passengers (2, 3, 4, etc.) get onto the plane and take their seat if it is available or picks one of the remaining seats at random if it is not.
What is the chance that the last passenger (passenger 100) will get his seat?
There is a 50 percent chance.
When the last passenger gets on seats 2 – 99 will be taken for sure. Each of these passengers would take their seats if they were available, so the only seat remaining at the end would be 1 or 100. So there is a 50 percent chance that passenger 100 would get seat 100.
Little Dan 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 Dan do to have the best chance of getting home with the money?
He just doesn’t take the bet. This gives him a 100 percent chance of getting the money home. If he takes the bet with 1 die he has a 50 percent chance of winning. If he takes the bet with 2 dice he has about a 56 percent chance of winning. If he takes the bet with 3 dice he has about a 42 percent chance of winning.
What's the angle between minute hand and hour hand at a quarter past three?
7.5 degrees.The minute hand is pointing directly at the ‘3’. The hour hand is 1/4 of the way between the ‘3’ and ‘4’. Since there are 12 numbers the angle between each number is 30 degrees. So the angle between the hands are 30 degrees * 1/4 = 7.5 degrees.
There are two ropes that both take exactly 1 hour to burn from end to end. You are unable to cut the rope. How can you burn the two ropes in a total of 45 minutes?
Start one of the ropes on fire from both ends and the other one from one end. After a half an hour one rope will be completely burnt and the other will be half burnt. At this point you light the final rope from the unlit side and it will take 15 minutes for the remaining half of the rope to burn, for a total of 45 minutes.
There are 100 coins scattered in a dark room. 90 have heads facing up and 10 are facing tails up. You cannot tell which coins are which. How do you sort the coins into two piles that contain the same number of tails up coins?
The piles don’t need to be the same size, so make a pile of 10 coins and a pile of 90 coins, flip all of the ten coins and it is guaranteed that the piles have the same number of tails.

Replace the question mark with mathematical symbols to make this equation work:
7 ? 7 ? 77 ? 7 ? 7 = 497
7 + 77 * 7 – 7 * 7 = 497.
A rat is placed at the beginning of a maze and must make it to the end. There are four paths at the start that he has an equal chance of taking: path A takes 5 minutes and leads to the end, path B takes 8 minutes and leads to the start, path C takes 3 minutes and leads to the end, and path D takes 2 minutes and leads to the start.
What is the expected amount of time it will take for the rat to finish the maze?
9 minutes. Each path has an equal chance of occurring and if B or D are chosen they will just add 8 or 2 minutes to the time because the rat must restart the maze: time = (1/4)*5 + (1/4)*(8 + time) + (1/4)*(3) + (1/4)*(2 + time). Time = 9 minutes.

Many more Math riddles

I know a number which when multiplied by multiple of 9 i.e 9 18 27 36 45 ... the output consist of number containing only one digit.
Can you identify the number ?
12345679
12345679 × 9 = 111111111 (only 1s)
12345679 × 18 = 222222222 (only 2s)
12345679 × 27 = 333333333 (only 3s)
12345679 × 36 = 444444444 (only 4s)
12345679 × 45 = 555555555 (only 5s)
He just doesn't take the bet. This gives him a 100 percent chance of getting the money home. If he takes the bet with 1 die he has a 50 percent chance of winning. If he takes the bet with 2 dice he has about a 56 percent chance of winning. If he takes the bet with 3 dice he has about a 42 percent chance of winning.
5. He makes 4 cigarettes with the 16 butts. Then he smokes them and has 4 more butts to make another cigarette.
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?
Both ends are nailed with the same nail. In order for the 10 foot chain to dip down 5 feet it must dip 5 feet down and 5 feet up, totaling the length of the chain.
What do you get if you add 3 to 300 five times?
303, 303, 303, 303, 303.
If there are four apples and you take away three, how many do you have?
You took three apples so obviously you have three.
If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?
The answer is PIZZA (PI x Z x Z x A)
A claustrophobic person gets on a train. The train enters a tunnel just as it is leaving the station.
Where is the best place for him to sit?
In the back. The train will be accelerating so it will be going faster when the back of the train enters the tunnel so a person in the back will spend less time in the tunnel.
When Robert was six years old he hammered a nail into his favorite tree to mark his height.
Five years later at age eleven , Robert returned to see how much higher the nail was.
If the tree grew by ten inches each year, how much higher would the nail be?
The nail would be at the same height since trees grow at their tops.
John has been hired to paint the numbers 1 through 100 on 100 apartments.
How many times with he have to paint 8?
20 times. (8, 18, 28, 38, 48, 58, 68, 78, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 98).
5+3+2 = 151022
9+2+4 = 183652
8+6+3 = 482466
5+4+5 = 202541
7+2+5 = ?
143547.
You have a flashlight that takes 2 working batteries. You have 8 batteries but only 4 of them work.
What is the fewest number of pairs you need to test to guarantee you can get the flashlight on?
7. If you break the batteries into 3 groups: Two groups of 3 and one group of 2. By doing this you guarantee that one of the groups has 2 working batteries. Both of the groups of 3 have 3 possible combinations of 2 batteries and the group of 2 only has 1 combination. So, 3 + 3 + 1 = 7 tries at most to find two working batteries.
Replace the '?' by any mathematical symbol to make the expression equal to 99.
18 ? 12 ? 2 ? 3 = 111.
18 x 12 ÷ 2 + 3 = 111.
What number do you get when you multiply all of the numbers on a telephone's number pad?
The number 0.
Can you arrange four nines to make it equal to 100.
99+9/9 = 100.
Mr. Smith has two children. If the older child is a boy, what are the odds that the other child is also a boy?
50 percent.
Divide 110 into two parts so that one will be 150 percent of the other. What are the 2 numbers?
44 and 66.
You have a glass of water that looks about half full. How can you tell, only using the glass of water itself, if the glass is half full or not?
The glass is a right cylinder.
Tip the glass of water until the water reaches the rim of the glass and if the water lines up perfectly with the bottom rim of the glass, it is half full.

Large number of people went to an party and they decided to make some fun at the bar.
The first person asks the barman for half a pint of beer.
The second person asks for a quarter pint of beer
The third person asks for one-eighth of beer and so on.
How many pints of beer will the barman need to fulfill the people need of beer ?
Just 1.
What is 2+2x2=?
If your answer is 8, it’s wrong. The real answer is 6. You always multiply first. Try it out on a calculator or your phone.
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?
2. The first page in each book is page number 1 regardless of how they are oriented and 1 + 1 = 2.

Want more math riddles?

Good for you, you made it to the end. Did you solve all of the math riddles? If so great job. I hope you like this category. I will of course add more math riddles if there is demand for them. In the meantime, I would like to direct your attention to all the other categories with riddles we have on this page. We also include jokes, quotes, insults and pickup lines. Have a good day.

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