Fiendish Maths Riddles Jan 17 - Can You Solve Them?

18th January 2017

We've got some fiendishly difficult maths riddles for you this month, try and solve them before scrolling down for the answer! Do share them with your friends and family and impress them with your giant brains...

Q. Jake weighs half as much as Joe, and John weighs three times as much as Jake. Together, they weigh 720 pounds. How much does each man weigh?

If Joe weighs twice as much as Jake, and John three times as much, dividing their total weight by six gives us Jake's weight (think x + 2x + 3x = 720). 720 divided by 6 tells us that Jake weighs 120 pounds, so Joe weighs 240 pounds and John weighs 360 pounds.

Q. Complete the sequence: 1=3, 2=3, 3=5, 4=4, 5=4, 6=3, 7=5, 8=5, 9=4, 10=3, 11=?,

6. You were looking fo the number of letters in the spelling of each number!

Q. Move 4 matchsticks to create 2 squares. The 2 squares must NOT be equal in size.

Got it yet? No............................................?

Keep trying....

Nearly there?

Here's the solution.

I'm there once in a minute, twice in a moment but never in a thousand years. Who am I?

A. The letter M!

Q. Today Batman noticed with great excitement that his Batmobiles odometer read 72927 kms - a numerical palindrome. How many minimum kms does he need to travel so his Batmobile's odometer shows another palindrome?

A. 110 kms

72927+110 = 73037 which is another palindrome.

Q. I add five to nine, and get two. The answer is correct, but how?

A. When it is 9am, add 5 hours to it and you will get 2pm.

Q. We all know that square root of number 121 is 11.

But do you know what the square root of the number "12345678987654321" is?

A. 111111111 - Explanation:

Square root of number 121 is 11

Square root of number 12321 is 111

Square root of number 1234321 is 1111

Square root of number 123454321 is 11111

Square root of number 12345654321 is 111111

Square root of number 1234567654321 is 1111111

Square root of number 123456787654321 is 11111111

Square root of number 12345678987654321 is 111111111

Q. If two’s company and three’s a crowd, what are four and five?

A. 9


Q. 100 people are standing in a circle. The person standing at position number 1 has a sword. He kills the person next to him with the sword and then gives the sword to the third person. This process is carried out till there is just one person left.

Why? Why not! Let Batman worry about that, he's on his way but he's busy driving 110kms first, he's a little OCD like that...

Anyway, can you figure out who survives the massacre?

A. The 73rd person will survive.


Until the number is the power of 2, the last person to survive will be the one who started it. But since the number here is not in the power of 2, we will take the greatest power of 2 that is less than the number which is 64.

100 - 64 = 36

36 people are killed as 2, 4, 6, ..., 72. Thus the sword will now be given to the 73rd person. Now he is the first person to start killing the remaining 64 people. Thus he will be the one to survive.

Q. Which has more value - 1 pound of $20 gold coins or half a pound of $40 gold coins?

A: Twice of half a pound is one pound