what does the below rebus means?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

Find the mistake in the below maths equations

A = 2
A(A-1) = 2(A-1)
A2-A = 2A-2
A2-2A = A-2
A(A-2) = A-2
A = 1

Find the smallest sentence with all the English alphabet.

What number when divided in half becomes zero?

In my garden, I have many trees but only one of them is the mango tree. In these mango trees, there are some mangoes(as expected).

But after a strong wind, there are neither mangoes on the tree nor on the ground. Explain?

A man has eighty-one cows ( numbered 1,2,3...81 as such). The beauty is that cow no. 1 gives 1ltr of milk, cow no. 2 gives 2ltrs of milk and so on. The man wants to equally distribute the cows among his nine sons so that each one of them gets the same quantity of milk.

What does below chemistry rebus means?

What runs around the whole yard without moving?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?