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

? : 3839 :: 11 : 1209

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.

Which tank will fill first?

Kareena is older than Katrina and younger than Karishma. Isabelle is younger than Bipasha and Karishma. Bipasha is older than Karishma. If Kareena and Isabelle are the same age, who's the youngest?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

If eleven plus two equals one, what does nine plus five equal?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

What do you get if you add 2 to 100 four times?

In a basket of apples,
when counted in twos, there was one extra
when counted in threes, there were two extra when counted in fours, there were three extra
when counted in fives, there were four extra
when counted in sixes, there was five extra.

However, if the apples were counted in sevens, no extra apple was left. Can you calculate the minimum number of apples that were present in the basket?

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?