Codechef Rating goes down by 162 points!!!!

I am new to codechef and just started a month before, After attempting several contest I manage to get my rating above 1200, But suddenly my rating get dropped by 162 points.
I just attempted the may long and able to solve 3 question but why my rating goes that much down?

@ayush9798 our rating is dependent on how other users participating in the same contest perform and how you perform. If you solved 3 questions - but other users with a similar rating as yours solved more questions or your ‘expected performance’ was higher, then your rating will drop.

The detailed rating mechanism is published here - Rating Mechanism | CodeChef

Best of luck and keep practicing!