Replace the question mark with the number below given a simple math problem.

What month of the year has 28 days?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

You have to fill the below given grid in a manner that every row and column contains the digits 1 to 6. Also, make sure that the squares that are connected with each other must contains the same digit.

What are the next two letters in the following series and why?
W A T N T L I T F S _ _

*Hint: Check Puzzle Title

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?

what one word does the below rebus identifies?

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?

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

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?