If A = {x: x is an odd number} and B = {y: y is a natural number}, then find A-B
A - B = { }
Which of the following are examples of the null set?
(i) Set of odd natural numbers divisible by 2.
(ii) Set of even prime numbers.
(iii) {x : x is a natural number, x < 5 and x > 7}
(iv) { y : y is a point common to any two parallel lines}