What is the centre of gravity?

what does the below math rebus puzzle mean?

A bomb exploded in a room full of married couples and no one died. How?

When monkey rotate the gear, which mark will be hit 1 or 2 ?

You have a basket containing ten apples. You have ten friends, who each desire an apple. You give each of your friends one apple.
Now all your friends have one apple each, yet there is an apple remaining in the basket.
How?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

You need to climb ten stairs. At every stair, you can either take one step up or you can jump two steps up.

In how many different ways you can climb 10 stairs?

What is the word or phrase?

It is a 5 letter word if you take away first letter it is something you get from sun, if you remove second letter you will get something to eat, if you remove third letter you get a word you use in pointing at and if you remove the fourth letter you get something to drink. What is it?

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