Complete the following series. It.s very logical:

1, 4, 5, 6, 7, 9, 11, __?

In the picture that is attached with this question, you can find a square which comprises of four little squares inside it. Consider this square to be made with matchsticks. You have to remove two matchsticks such that only two squares remain instead of five.How will you do it ?

In a concert, Christina is performing a dance show with her group.
At 10:00, she and her crew were dancing in an absolutely straight line. At that time Christina was standing in 4th position from both the front and back end of the row.

What was the size of her crew?

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

Find three numbers such that When we multiply three numbers, we will get the prime numbers. The difference between the second and the first number is equal to the third and second.

I had an infinite supply of water and 5 litres and 3 litres jars.

How would you measure exactly 4 litres in the least number of steps?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?