Question

Using repeated subtraction method, find the HCF of the following:

42 and 70

Answer 1

Let number be m and n

m > n

We do m – n and the result of subtraction becomes new ‘m’. if m becomes less than n, we do n – m and then assign the result as n. We should do this till m = n. When m = n then ‘m’ is the HCF.

42 and 70

now m = 70, n = 42

70 – 42 = 28

now m = 42, n = 28

42 – 28 = 14

now m = 28, n = 14

28 – 14 = 14

now m = 14, n = 14

we stop here as m = n

∴ HCF of 42 and 70 is 14