monthly test

1. Let A = {x/x is positive integer that is divisible by 2}. B = { x/x is a positive integer that is
   divisible by 3}. C = {x/x is appositive integer that is divisible by 5}. List the elements of the
   sets A, B, C. Find (a) A∩ (B∩C) and (b) (A∩B) ∩C. Show that A∩ (B∩C)= (A ∩ B) ∩ C
   6.Let A = {x/x is a positive integer less than 7} and B = {x/x is an integer land -3 ≤ x ≤4}.
   List the number of A and B, and then write down A ∪ B.
2. Let A = {x/x is an integer, 0<x<6} and B = {x/x is a positive integer less than 13 and x is
   a multiple of 3}. List the number of A and B, and find A ∪ B.
3. If P = {x/x2 + 2x -3} and Q = {x/x is an integer, -1 ≤ x ≤ 4}, find P ∩ Q and P ∪ Q.

Exercise 1.4

1. Find the set B\A and A\B in the following.
   (a) A = { 1,2,3,4,5,6} , B = { 3,5} (b) A = { p,q,r,s} , B = { x,y,z}
   (c) A = { 1,2,3} , B = { 1,2,3,4}