Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

One day, John and his friends were playing around. Jacob hit something with a Pin and it popped. John's dad came into the room that very moment, but he wasn't mad. In fact, he was smiling. What did Jacob hit?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

What jumps when it walks and sits when it stands?

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

How many bananas can you eat if your stomach is empty?

How many Watermelons are there in the below picture?

What part of the chicken has the most feathers?

What English word has three consecutive double letters?