Math Riddles

One brick is one kilogram and half a brick heavy. What is the weight of one brick?

One fourth of the population of a newly discovered planet have 4 legs. The rest have two legs. There are 60 legs total. How big is the population of the newly discovered planet?

One out of 9 otherwise identical balls is overweight. How can it be identified after 2 weighings?

Place three matches on a table. Tell a friend to add two more matches to make eight.

Placed above it makes greater things small. Placed beside it makes small things greater. In matters that counts it always comes first. Where others increase it keeps all things the same. What is it?

Raise me none, and I’m unbeaten. Raise me once, I am as well. Raise me thrice, and I am eaten. All said right, but wrongly spelled. Who am I?

Sally is 54 years old and her mother is 80, how many years ago was Sally’s mother three times her age?

The ages of a father and son add up to 66. The father’s age is the son’s age reversed. How old could they be?

The combined age of Jack and John is 49. Jack is twice as old, as John was when Jack was as old as John is now. How old are the brothers?

There are 12 kids in a classroom. 6 kids are wearing socks and 4 are wearing shoes. 3 kids are wearing both. How many are bare feet?

There are 2 ducks in front of 2 other ducks. There are 2 ducks behind 2 other ducks. There are 2 ducks beside 2 other ducks. How many ducks are there?

There are 25 red balls, 47 green balls and 3 blue balls in a basket. There is a blind man. What is the minimum number of balls that the blind man has to pick to make sure that there are at least 2 balls of different colors?

There are two ducks in front of a duck, two ducks behind a duck and a duck in the middle. How many ducks are there?

There is a three digit number. The second digit is four times as big as the third digit, while the first digit is three less than the second digit. What is the number?