Question

Write the following sets in roster form: 

(i) A = {x : x is an integer and – 3 < x < 7} 

(ii) B = {x : x is a natural number less than 6} 

(iii) C = {x : x is a two-digit natural number such that the sum of its digits is 8} 

(iv) D = {x : x is a prime number which is divisor of 60} 

(v) E = The set of all letters in the word TRIGONOMETRY. 

(vi) F = The set of all letters in the word BETTER. 

(vii) G = The solution set of the equation x² + x - 2 = 0. 

(viii) H = {x : x is a positive integer and x² < 40}

Answer 1

(i) A = {-2, -1, 0, 1, 2, 3, 4, 5, 6} 

(ii) B = {1, 2, 3, 4, 5} 

(iii) C = {17, 26, 35, 44, 53, 62, 71, 80} 

(iv) D = {2, 3, 5} (v) E = {T, R, I, G, 0, N, M, E, Y} 

(vi) F = {B, E, T, R} 

Given equation is x² + x – 2 = 0 

⇒ (x – 1)(x + 2) = 0 i.e., = 1,-2 

∴ G = {1,-2} 

(viii) H ={1, 2, 3, 4, 5, 6}