With the help clues provided in the image, can you find the 5 digit key?

I am Huge on Sunday and Saturday.
I am small from Tuesday to Thursday.
I do not exist on Monday and Friday.
Who am I?

I have 50 feet long of cloth, I need to create 50 handkerchiefs each size of 1 foot. I take one minute to cut a 1-foot handkerchief. So how long will it take to cut 50 handkerchiefs?

A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?

What is next number in the pattern below:

131 517 192 123 ?

Can you find the thief by just looking at the picture below?

I have a mouth but I don't eat.
I have a bank but have no money.
I have a bed but i dont sleep.
I wave but have no hands.

Who Am I ?

Yesterday I fell from 30 feet high ladder but I don't get hurt. Why?

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?

A Miser man decided to go on a vacation for a month. He goes to the bank and asks for a trip loan of $500. The bank officer asks the man that the loan can only be approved when he mortgage some valuable thing at the bank. Miser man mortgages his only car whose worth was a whopping $80000. The Bank officer laughed at him and approve the loan instantly. After vacation when the miser man returns, the bank officer asked him "Are you an idiot, why is your mortgage such an expensive car for such a short loan?".

Miser man replied with some reason and the bank officer agreed that the miser man is actually not an idiot.

What did miser man reply to the bank loan officer?.