Find the common factors and the HCF of the following numbers: Class 7
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Expert Answer
Find the common factors and the HCF of the following numbers: Class 7
Question 1.
Find the common factors and the HCF of the following numbers: Class 7
How do we directly find the HCF without listing all the factors?
(a) 50, 60
Solution:
Common factors are 2, 5 and 10.
HCF = 2 × 5 = 10.
(b) 140, 275
Solution:
Common factor - 5, H.C.F. = 5
(c) 77, 725
Solution:
77 = 7 × 11
725 = 5 × 5 × 29
No common factor. So, HCF = 1.
(d) 370, 592
Solution:
Common factors are 2, 37, 74.
HCF = 2 × 37 = 74
(e) 81, 243
Solution:
Common factors are 3, 9, 27 and 81.
HCF = 3 × 3 × 3 × 3 = 81.
By repeated division process and also the method of prime factorisation as done above in (a) to (e).