What work can one never finish?

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?

The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

I am sometimes honest
Sometimes dishonest
I can be sweet and also bitter
I can hurt you real bad and
also make u smile and blush ☺️
What am I?

Can you find a five letter word that is left with only two letters if one is removed?

Find the last number in the series below:

voN luJ yaM raM ---

What can you see in the middle of March and April that you can never see in any other month?

If I put in one canary per cage, I have one bird too many. If I put in two canaries per cage, I have one cage too many. How many cages and canaries do I have?

Can you solve the maths in the below-given picture equation?

What you cannot hold but it is yours?