What happened when the wheel was invented?

A quarter is one-fourth of a dollar but Mr. John has changed the equation as below :

DOLLAR * 4 = QUARTER

Can you replace each letter with a digit to make the above solution correct?

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).

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?

I’m orange, I wear a green hat and I sound like a parrot. What am I?

What goes up but never comes down?

A man dies of old age on his 25 birthday. How is this possible?

A deaf and mute man goes to the train station. Tickets for the train are 50 cents each. The man goes to the ticket booth and hands the man inside just a dollar. The man in the booth hands him two tickets.

How did the man in the booth know to give him two tickets without even looking at him?