A maths symbol is hidden in the below Bar Graph. Can you decipher it?

A large water tank has two inlet pipes (a large one and a small one) and one outlet pipe. It takes 3 hours to fill the tank with the large inlet pipe. On the other hand, it takes 6 hours to fill the tank with the small inlet pipe. The outlet pipe allows the full tank to be emptied in 9 hours.

What fraction of the tank (initially empty) will be filled in 0.64 hours if all three pipes are in operation? Give your answer to two decimal places (e.g., 0.25, 0.5, or 0.75).

Who has married many women but was never married?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

It has five wheels, though often think four, You cannot use it without that one more, You can put things in it, you can strap things on top, You can't find it in the market, but you can still go shop. What is it?

By moving exactly three matchsticks can you make the below equation true.It can be solved by 3 ways.

Two in a corner, one in a room, zero in a house, but one in a shelter. What am I?

A clock loses 10 minutes each hour. If the clock is set correctly at noon, what time is it when it reads 3 PM?

What do you see in the image below

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?