Can you make four (4) nines (9) equal 100?

Forwards I am heavy, backward I am not. What am I?

What does the below rebus puzzle mean?

There is so small cabin inside a deep forest.
All the forest burned out to worst possible but the inside of the cabin is still the same.
However all the person inside the cabin die.

How come ?

If a wheel has 54 spokes, how many spaces are there between the spokes?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

Using eight eights and addition only, can you make 1000?

Why Wine Glass Stem is so long?

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).

When can we add 2 to 11 and get 1 as the correct answer?