Not everything about maths is boring, in fact you can have a lot of fun with different maths riddles.  Here are five of our favourite maths riddles to challenge your brain and to puzzle your friends and family.  Answers are at the bottom!

  1. A farmer is trying to cross a river with a bag of seed, a hen, and a fox. The farmer’s boat is only big enough to take himself and one other item per trip. The hen can’t be left on her own with the corn or she will eat it all. Likewise the fox cannot be left with the hen, or the hen will be eaten by the fox. How does the farmer get all three items across the river?

 

  1. A solo dice game is played where, on each turn, a normal pair of dice is rolled. The score is calculated by taking the product, rather than the sum, of the two numbers shown on the dice.

 

On a particular game, the score for the second roll is five more than the score for the first; the score for the third roll is six less than that of the second; the score for the fourth roll is eleven more than that of the third; and the score for the fifth roll is eight less than that of the fourth. What was the score for each of these five throws?

 

  1. The day before yesterday I was 26 and the next year I will be 29. This is true only one day in a year.

What day is my birthday?

 

  1. A teacher says: I’m thinking of two natural numbers greater than 1. Try to guess what they are.

The first student knows their product and the other one knows their sum.

 

First: I don’t know the sum.

Second: I knew that. The sum is less than 14.

First: I knew that. However, now I know the numbers.

Second: And so do I.

What were the numbers?

 

  1. A woman has 7 daughters and they each have a brother, how many children does she have?

 

 

Answers

  1. First, the farmer takes the hen across and leaves her on the other side. Next, he comes back, loads the fox onto his boat, and takes him back across the river. He drops off the fox on the opposite bank, picks the hen back up, and brings her back to the original side. He swaps the hen for the seed, and returns to the far bank with the seed – leaving it with the fox who won’t eat it. Finally he returns once more to the original side to get the hen. Now everyone is on the other side in harmony.
  2. 10 for the first roll.

15 for the second roll.

9 for the third roll.

20 for the fourth roll.

12 for the fifth roll.

  1. 31st of December. They spoke about it on the 1st of January.
  2. The numbers were 2 and 9.
  3. 8 children, the sisters have just one brother!