9. Which of the following is null set
a) {x; x is an even prime number}
b) {x; x2 = 4,xeZ }
c) {x; x² - 2 = 0 and x is a natural number} d) {x; x is a vowel which proceed u}
Answers
Answer:
(i) A set of odd natural numbers divisible by 2 is a null set because no odd number is divisible by 2.
(ii) A={2}.
A set of even prime numbers is not a null set because 2 is an even prime number.
(iii) {x:x is a natural number,x<5 andx>7} is a null set because a number cannot be simultaneously less than 5 and greater than 7.
(iv) {y:y is a point common to any two parallel lines} is a null set because parallel lines do not intersect. Hence, they have no common point.
Answer:
(i) A set of odd natural numbers divisible by 2 is a null set because no odd number is divisible by 2.
(ii) A={2}.
A set of even prime numbers is not a null set because 2 is an even prime number.
(iii) {x:x is a natural number,x<5 andx>7} is a null set because a number cannot be simultaneously less than 5 and greater than 7.
(iv) {y:y is a point common to any two parallel lines} is a null set because parallel lines do not intersect. Hence, they have no common point.