Can you solve the below algebraic mathematical equation?

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

In a competitive exam, each correct answer could win you 10 points and each wrong answer could lose you 5 points. You sat in the exam and answered all the 20 questions, which were given in the exam.
When you checked the result, you scored 125 marks on the test.

Can you calculate how many answers given by you were wrong?

A man dies of old age on his 25 birthday. How is this possible?

Can you write down eight eights so that they add up to one thousand?

Can you find out the remainder when 3^300 is divided by 5?

Two guards were guarding the camp.Guard-1 was looking towards the south to make sure no threat is coming from the road.Guard-2 was looking at the north to make sure no threat is coming from the top. Suddenly Guard-1 ask the Guard-2 why he is smiling?How Guard-1 knows that Guard-2 is smiling?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

Two men play a dice game involving roll of two standard dice. Man X says that a 12 will be rolled first. Man Y says that two consecutive 7s will be rolled first. The men keep rolling until one of them wins.

What is the probability that X will win ?

If your uncle’s sister is not your aunt, what relation is she to you?

There was a competition where the contestants had to hold something. At the end of the event, the winner was a person who had no hands or feet. What was it that the contestants had to hold?