Keyboard words are not in alphabetical order, Why?

You have four chains. Each chain has three links in it. Although it is difficult to cut the links, you wish to make a single loop with all 12 links. What is the fewest number of cuts you must make to accomplish this task?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

In a boat, the father of a sailor's son is sitting with the son of the sailor. However, the sailor is not present on the boat.

Can this even be possible?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

They are three errirs in this question. Can you find them?

If Rajina's daughter is my daughter's mom, who am I to Rajina?

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?

Open a Laptop which is password protected. Hint for the password is given as below:

1 mobile 3 books 2 Boards 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches