Worked example 1 The following three sets are given:
핌 = {the fi rst eleven natural numbers}, X = {1, 2, 5, 6, 7, 9}, Y = {1, 3, 4, 5, 6, 8} and Z = {3, 5, 6, 7, 8, 10} (i) List the elements of 핌 . (ii) Represent this information on a Venn diagram. (iii) Show that X\( Y\Z ) ≠ ( X\Y )\Z . (iv) Show that X∩(Y∩Z)= (X∩Y)∩Z .
(v) Show that Z∪(X∪Y)= X∪(Y∪Z) .
(vi) If a number is chosen at random, calculate the probability that it is a prime number.
Solution (ii)
✓
(iii)
Set diff erence is not associative or commutative.