I can write cow in 13 letters.

Can You?

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).

Using the clues below, what four numbers am I thinking of?

The sum of all the numbers is 31.
One number is odd.
The highest number minus the lowest number is 7.
If you subtract the middle two numbers, it equals two.
There are no duplicate numbers.

Which is the rope you never skip with?

I am sure no one can have two things for dinner. what are they?

Why are all black people so quick ?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

The dirtier I get, the whiter I look. Who am I?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.