What four weights can be used to balance from 1 to 30 pounds?

How many times can you subtract the number 5 from 25?

You need to pick one entry from pot A and one from pot B to have a perfect match. Can you do it?

Can you find out the missing number in the grid?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

A lion and its tamer are standing inside a cage that measures 1 unit in radius. Both of them can effortlessly run at the speed of 1 unit maximum.

1) Suppose the lion is hungry, will he be able to eat up the tamer?
2) If yes, how long can the tamer survive?

Why is a river so rich ?

I taste better than I can smell. Who am I?

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

What does this simple rebus mean?