Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

An inspection by the superintendent of St. Joseph School was scheduled on the next day. The class teacher Jenifer knew that he would be asking questions from her class and she would have to choose a pupil to answer. To offer a perfect impression over him, the teacher explained certain instructions to the students to maximise the chances of getting correct answer every time.

What did she say to the students?

The measurement of time, That can't be found on a clock, But can be looked upon on a map.

Who is He ?

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 is the fastest way to double your money?

Can you find out a way through which you can make five squares out of the given figure by moving just six match sticks?

You need to remove two matchsticks to make the below equation true. Can you do it ?

Find the next number in the sequence

1, 2, 6, 21, 88, __?

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?

Below, you can see three complete equations and one incomplete. Based on the three complete ones, can you complete the incomplete one?

5 $ 4 $ 3 $ 9 = 4215
6 $ 9 $ 2 $ 6 = 3816
4 $ 7 $ 3 $ 3 = 1122
7 $ 2 $ 7 $ 4 = ____