Can you spot what's wrong with the following sentence?

PETER WAS ANGRY AT
HIMSELF BECAUSE HE
ACCIDENTALLY LEFT THE
THE KEYS TO HIS CAR
AT HIS FRIEND'S HOUSE.

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

If 1+9+8=1, what is 2+8+9?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

On a windy rainy night , I was driving in my car.
When i reach the bus stand , i see three people waiting for the bus.

1. An old lady who needs an immediate medical attention
2. My Best Friend
3. Girl whom i love from childhood

My car is a two seat, so can you tell me , what i have done in this situation ?

What is harder to catch the faster you run?

What is black when you buy it, red when you use it, and gray when you throw it away?

The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?