Solve the equation in the image by looking at the pattern closely.

In a university, a professor gave a set of three problems to the three brilliant students of his class. See the image for the questions.

I know a nine-letter word having only one vowel.
Do you ?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

As a whole I am both
safe and secure.

Behead me and I become
a place of meeting.

Behead me again and I am
the partner of ready.

Restore me, and I become
the domain of beasts.

What am I?

What does the below rebus puzzle mean?

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

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?