The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

A man was going to bleach his socks because they had gotten muddy the day before. As he was pouring the bleach into the washing machine, he spilt some on the floor. He got some cleaning fluid and mopped it up with a rag. Minutes later he was dead. What killed him?

Can you tell a 3D object that has just two surfaces?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

How many triangles can you count in the figure given?

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?.

What 5-letter word typed in all capital letters can be read the same upside down?

I have Rs.50 and I spend it in the way as below.

What English word has three consecutive double letters?