What does this below rebus puzzle mean?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

You need to climb ten stairs. At every stair, you can either take one step up or you can jump two steps up.

In how many different ways you can climb 10 stairs?

Why is a river so rich ?

Find three numbers such that When we multiply three numbers, we will get the prime numbers. The difference between the second and the first number is equal to the third and second.

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?

A mathematics teacher took exams for his students. Out of the total students, 25% passed both the tests included in the exam. However, only 42% were able to clear the first test.

Can you find out the percentage of those students who passed the first test and also passed the second test?

It is deaf, Dumb and Blind!!!

Still, always tells the truth. What is it?

Who has married many women but was never married?

There is a box. The area of its top is 240 square units, the area of the front is 300 square units and the area of the end is 180 square units.

Can you calculate the dimensions of this box with the given data?