What is both possible and impossible at the same time?

What is the next number in this matchsticks series riddle?

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.

What is the word or phrase?

Can you spot the man between the coffee bean in the picture below ?

The chance of Mr John winning the lottery is 10%. All participants lined up and Mr John is 4th in the row. The first three participants lose the lottery.

What is the chance of Mr John now?

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?

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?

People make me, save me, change me, raise me. What am I?

What will you call your mother's brother's brother-in-law?