How many triangles are there on the puzzle below?

A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?

What number do you get when you multiply all of the numbers on a telephone's number pad?

Which Number is the odd one out?

A) 7145
B) 2716
C) 5321
D) 4135

I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?

The measurement of time, That can't be found on a clock, But can be looked upon on a map.

Who is He ?

Can you find the thief by just looking at the picture below?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not-rounded numerals equals 24.

There are three boxes of different sizes with three cupcakes inside each of the boxes in Christina's kitchen. At night her daughter wakes up and goes to the kitchen. She opens a box and eats all three cakes.

But in the morning Christina finds out that each box still had three cupcakes. How?