Can you name an animal whose killing cannot be performed without spilling your own blood?

Manish has to secure 40% marks to pass his B.tech final exams.
He got just 40 marks and failed by 40-marks.

What is the maximum marks?

13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?

Name a key which is hardest to turn.

I can sizzle like bacon,
I am made with an egg,
I have plenty of backbone, but lack a good leg,
I peel layers like onions, but still remain whole,
I can be long, like a flagpole, yet fit in a hole.

Why is it very easy to weigh a fish?

Can you move 2 matchsticks to form four equal sized squares.

What is the word or phrase below?
R | E | A | D

I have teeth but i don't bite. Who Am I ?

In the following picture, E is going to slide the object down and as per the terrain and the physics, the round object is going to travel all the way till the end. Now, can you analyze who all people will die when it happens?