In the image below, can you find the value of an angle(y)

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?

How far can you walk into the woods?

If an electric train is travelling south, then which way is the smoke going?

The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

I am white when I am dirty, and black when I am clean. What am I?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

I don't get anymore wetter, no matter how much rain falls on me.

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

A man dies of old age on his 25 birthday. How is this possible?