Can you find out which number multiplied by itself will give the output as 12345678987654321?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

We have four gears with below features=> Both Gear A and D has 60 teeth=> Gear B has 40 teeth=> Gear C has 20 teeth=> Every two minutes, Gear B makes 25 full turns.What is the relative speed of Gear A and Gear B?

What is the value of 1/2 of 2/3 of 3/4 of 4/5 of 5/6 of 6/7 of 7/8 of 8/9 of 9/10 of 1000?

John was a very careless driver, so his owner Jacob gave him an offer that he will get an incentive of Rs.30 for every bottle box he delivered without breaking it and he will be charged Rs.90 for every bottle box he broke. Jacob gave John 100 bottles-box to deliver. After delivery, Jacob paid John Rs.2400. How many bottles-box did John break?

You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?

What begins with T, ends with T, and has T in it?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

You need to move three matchsticks to form three squares. Can you do it?