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?

If 21x = 79x, what is the value of x?

A mules travels the same distance daily.
I noticed that two of his legs travels 10km and the remaining two travels 12km.
Obviously two mules legs cannot be a 2km ahead of the other 2.

The mules is perfectly normal. So how come this be true ?

A and B have a certain number of chocolates with them. If B gives one chocolate to A, they will have an equal number of chocolates. But if A gives one chocolate to B, then A will be left with half the number of chocolates that B has.

Can you find out the number of chocolates they have right now?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

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

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

In a basket of apples,
when counted in twos, there was one extra
when counted in threes, there were two extra when counted in fours, there were three extra
when counted in fives, there were four extra
when counted in sixes, there was five extra.

However, if the apples were counted in sevens, no extra apple was left. Can you calculate the minimum number of apples that were present in the basket?

We know that the number 7 is the prime followed by a cube. Which next number is also a prime followed by a cube?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?