Why do we preferably have round manhole covers and not square ones?

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

John, a 5-year-old boy, was really fond of the chocolates. He asked his Mother to give him some money to buy his favourite chocolates. His Mother gave him $45. He went to the shopkeeper and asked, "How much is one chocolate for?". The shopkeeper said $3 for one chocolate. Also, if you give me the wrappers of three chocolates, I will give you one for the exchange.
In total, how much chocolate could John eat?

Make a sentence consisting of three words that have the whole alphabet.

Which point will the car reach to go out?

A B C D E F G H

These are the letters given to you. Now you have to find out the letter that comes two to the right of the letter which is immediately to the left of the letter that comes three to the right of the letter that comes midway between the letter two to the left of the letter C and the letter immediately to the right of the letter F.

13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?

If you’ve got me, you want to share me; if you share me, you haven’t kept me. What am I?

What always comes into a house through the keyhole?

Why Wine Glass Stem is so long?