Question

Find the HCF of the numbers in each of the following, using the division method:
10. 58. 70
13. 1965, 2096
16. 754. 1508, 1972
11. 399. 437
14. 2241, 2324
17. 391. 425, 527
12. 1045, 1520
15. 658, 940, 1128
18. 1794. 2346, 4761​

Answer 1

Answer:

) 84, 98

Ans: All the factors of 84 are 2 x 2 x 3 x 7

All the factors of 98 are 2 x 7 x 7

Common factors of 84 and 98 are 2 x 7

Thus, the highest common factor of 84 and 98 is 7

Hence, HCF of 84 and 98= 7

(2) 170, 238

Ans: All the factors of 170 are 2 x 5 x 17

All the factors of 238 are 2 x 7 x 17

Common factors of 84 and 98 are 2 x 17

Thus, the highest common factor of 170 and 238 is 17

Hence, HCF of 84 and 98= 17

(3) 504, 980

Ans: All the factors of 504 are 2 x 2 x 2 x 3 x 3 x 7

All the factors of 980 are 2 x 2 x 5 x 7 x 7

Common factors of 504 and 980 are 2 x 2 x 7

Thus, the highest common factor of 504 and 980 is 7

Hence, HCF of 504 and 980= 7

(4) 72, 108, 180

Ans: All the factors of 72 are 2 x 2 x 2 x 3 x 3

All the factors of 108 are 2 x 2 x 3 x 3 x 3

All the factors of 180 are 2 x 2 x 3 x 3 x 5

Common factors of 72, 108 and 180 are 2 x 2 x 3 x 3

Thus, the highest common factor of 72, 108 and 180 is 3

Hence, HCF of 72, 108 and 180= 3

(5) 84, 120, 138

Ans: All the factors of 84 are 2 x 2 x 3 x 7

All the factors of 120 are 2 x 2 x 2 x 3 x 5

All the factors of 138 are 2 x 3 x 23

Common factors of 84, 120 and 138 are 2 x 3

Thus, the highest common factor of 84, 120 and 138 is 2 x 3

Hence, HCF of 84, 120 and 138= 3

(6) 106, 159, 371

Ans: All the factors of 106 are 2 x 53

All the factors of 159 are 3 x 53

All the factors of 371 are 7 x 53

Common factors of 106, 159 and 371 is 53

Thus, the highest common factor of 106, 159 and 371 is 53

Hence, HCF of 106, 159 and 371= 53

(7) 272, 425

Ans: All the factors of 272 are 2 x 2 x 2 x 2 x 17

All the factors of 425 are 5 x 3 x 17

Common factors of 272 and 425 is 17

Thus, the highest common factor of 272 and 425 is 17

Hence, HCF of 272 and 425= 17

(8) 144, 252, 630

Ans: All the factors of 144 are 2 x 2 x 2 x 2 x 3 x 3

All the factors of 252 are 2 x 2 x 3 x 3 x 7

All the factors of 630 are 2 x 3 x 3 x 5 x 7

Common factors of 144, 252 and 630 are 2 x 3 x 3

Thus, the highest common factor of 144, 252 and 630 is 18

Hence, HCF of 144, 252 and 630= 18

(9) 1197, 5320, 4389

Ans: All the factors of 1197 are 3 x 3 7 x 19

All the factors of 5320 are 2 x 2 x 2 x 5 x 7 x 19

All the factors of 4389 are 3 x 7 x 11 x 19

Common factors of 1197, 5320 and 4389 are 7 x 19

Thus, the highest common factor of 1197, 5320 and 4389 is 19

Hence, HCF of 1197, 5320 and 4389= 19