Question

Exercise
1B
BASIC LEVEL
1. Find the highest common factor of each of
the following sets of numbers.
(a) 12 and 30 (b) 84 and 156
(c) 15, 60 and 75 (d) 77, 91 and 143​

Answer 1

Answer:

answer is (b) 84and156

Answer 2

Answer:

Option B is correct

Explanation:

(a) 12 and 30

12 = 2×2×3

30 = 2×3×5

HCF = 2×2×3×5

HCF = 60

(b) 84 and 156

84 = 2×2×3×7

156 = 2×2×3×13

HCF = 2×2×3×7×13

HCF = 1092

(c) 15, 60 and 75

15 = 3×5

60 = 2×2×3×5

75 = 3×5×5

HCF = 2×2×3×5×5

HCF = 300

(d) 77, 91 and 143

77 =7×11

91 = 7×13

143 = 11×13

HCF = 7×11×13

HCF = 1001

so, the highest common factor of each of the sets of numbers is (b) 84 and 156 = 1092

hope it helps you :)