Which number should replace the question mark?

Why Aeroplane windows are round?

On rolling two dices (six-sided normal dice) together, what is the probability that the first one comes up with a 2 and the second one comes up with a 5?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

Spot 5 differences in two Christmas tree below:

I don't get anymore wetter, no matter how much rain falls on me.

At my favorite fruit stand,
an orange costs 18,
a pineapple costs 27,
and a grape costs 15.
Using the same logic, can you tell how much a mango costs?

In the picture, you can see a chess board. On the top left position, the K marks a knight. Now, can you move the knight in a manner that after 63 moves, the knight has been placed at all the squares exactly once excluding the starting square?

Can you count the number of squares in the figure below?

There are five vowels (a, e, i, o, u) in the English language.
Can you tell us a word that contains all these vowels?