You are mixing a mixture of cement and Sand with five gallons of water. You have a garden hose giving you all the water you need. The problem is that you only have a four-gallon bucket and a seven-gallon bucket and neither has graduation marks. Find a method to measure five gallons.

In the picture given below, can you find out which digit will take place of the question mark?

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

If six children and two dogs were under an umbrella, how come none of them got wet?

Find three whole, positive numbers that have the same answer when multiplied together as when added together.

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

Speaking of rivers, a man calls his dog from the opposite side of the river. The dog crosses the river without getting wet, and without using a bridge or boat. How?

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211