the number 1 to 20 are written on pieces of paper and put in the box. if a piece of paper is picked at random, what is the probability of picking a paper with: an odd number, a prime number, a multiple of 3 and a square number

Answer 1

see other post. Now to some advice: the school subject box is to guide the right tutors to their unanswered posts. Why are you listing all those subjects on a math post? Stop it please