what does the below math rebus puzzle mean?

Make the seating arrangement of 10 children in such a way that there are 5 rows with 4 children in each row.

A boy collects white seashells from the sea and brings them home every night. When he has enough of them, he decides to sell them to a trader.

The trader is ready to buy the shells and he asks the boy about the quantity. At this, the boy starts calculating. He has a giant box that contains 3 mini boxes. Two of them have another mini box inside. If the giant box can hold 50 shells, how many brown shells can he sell to the trader?

I look at you, you look at me, I raise my right, you raise your left. What am I?

What does this rebus means ?

PROG WORKRESS

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different. How do you measure 45 minutes?

If you say my name, I will no longer exist. What am I?

Wednesday, Steve and Pam go to a restaurant to eat lunch. After eating lunch, they pay the bill. But Steve and Pam do not pay the bill. So…who does?

What is next number in the pattern below:

131 517 192 123 ?