When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

Can you replace the X (both small and big x) with the numbers between 1 to 19 such that all the rows of 3 numbers between X (big x) sum to 23?

The centre of the third figure is empty. What digit should fit inside?

If I put in one bird per cage, I have one bird too many. If I put in two bird per cage, I have one cage too many. How many cages and birds do I have?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

You walk into a room and see a bed. On the bed, there are two dogs, five cats, a giraffe, six cows, and a goose. There are also three doves flying above the bed. How many legs are on the floor?

What Deficiency does the below rebus represent?

VIT_MIN

How many letters are in the alphabet?

In a school, there are four subjects. Seventy percent of students study English, seventy five percent of students study Science, eighty five percent of students study Mathematics and eighty percent of students study Spanish.

Can you calculate the percentage of students that study all four subjects?