When we see 2 but call 10?

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?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

The host of a game show offers the guest a choice of three doors. Behind one is an expensive car, but behind the other two are goats.
After you have chosen one door, he reveals one of the other two doors behind which is a goat (he wouldn't reveal a car).

Now he gives you the chance to switch to the other unrevealed door or stay at your initial choice. You will then get what is behind that door.

You cannot hear the goats from behind the doors, or in any way know which door has the prize.

Should you stay, or switch, or doesn't it matter?

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

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

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

In a football game, Christina defeated Teresa by 2 - 0 but no man from either side scored. How can this be possible?

The more of this there is, the less you see. What is it?

I have Rs.50 and I spend it in the way as below.