Do You See It?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

A man embarked on a questionnaire game. He kept asking the same question to whomever he found. The answer each time was different.

Can you guess what the question was?

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?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

How is a fly different from a mosquito?

I shave every day, but my beard stays the same. What am I?

A man was gazing through the window of the 23rd floor of the building. He suddenly opened the window and jumped on the other side of the window. On landing on the floor, there was not a sheer mark of injury on him.

How can that be possible if he did not use any kind of parachute and did not land on a soft surface?

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?

What can you see in the middle of March and April that you can never see in any other month?