Can you count the number of triangles in the given picture?

Count The number of F's in the paragraph below:

"FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS"

It belongs to you, but other people use it more than you do. What is it?

Thirty friends were on a hiking trip when they decided to enjoy the bonfire. They assembled for it and agreed to play a game. For that, they divided themselves into five teams with seven members each, forming five rows.

How did they manage to achieve this formation?

No matter how little or how much you use me, you change me every month. What am I?

If,

Akriti = 631
Levis = 521
Sroti = 521
Aneel = 533
Then,
Sunil =?

A person was killed at a house party. When the police arrive, there are six people present in the house who are the friends of the victim. The name of the friends is Rohit, Aman, Nick, Gagan, and Randy.

Near the dead body, they find a few numbers written with blood by the victim on the floor. The numbers are 8, 5, 4, and 11.

The police arrests one of the friends for the murder. Whom did they arrest and why?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

Solve the mathematical equation in the picture below.