Can you solve the below algebraic mathematical equation?

(J+O+I+N+T)3 = JOINT

A man looks at a painting in a museum and says, “Brothers and sisters I have none, but that man’s father is my father’s son.” Who is in the painting?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

A man has eighty-one cows ( numbered 1,2,3...81 as such). The beauty is that cow no. 1 gives 1ltr of milk, cow no. 2 gives 2ltrs of milk and so on. The man wants to equally distribute the cows among his nine sons so that each one of them gets the same quantity of milk.

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

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

In one of the popular batman series movie "Batman Forever", there was a riddle that goes like "Tear me off and then scratch my head and I was red then and now I am back. Who am I?

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

What does below Rebus say?

XLR8