Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?

Find the next number in the sequence

1, 2, 6, 21, 88, __?

The first two letters signify a male, the first three letters signify a female, the first four letters signify a great, while the entire world signifies a great woman. What is the word?

Solve the equation in the image by looking at the pattern closely.

How many triangles are there on the puzzle below?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

Can you place six X (crosses) in below board without making three in a row in any way ?

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

Find out a multi-digit number that if multiplied by the number 9 or any of its multiplications products (i.e. 18, 27, 36, 45,..) will result in the multiplication factor repeated (n) number of times.