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

Can you solve below mathematical equation?

2^1234 - 2^1233

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).

Find the combined weight of the Cat, Dog and Rabbit in the given picture.

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?

I am an odd number. Take away a letter and I become even. What number am I?

A girl is twice as old as her brother and half as old as her father. In 50 years, her brother will be half as old as his father. How old is the daughter now?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

A Shopkeeper collects 71 rupees in the form of 20 paisa and 25 paisa.
He collects a total of 324 coins.

Can you tell me how many number of 20-paisa and 25-paisa he got?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?