Question

lcm and hcf of 20,15,21 by prime factorising

Answer 1

Answer:

L.C.M. :-

3  20, 15, 21

5  20, 5, 7

    4 , 1, 7

Therefore,

3*5*4*7 = 420.

H.C.F. :-

2 20        3 15         3 21

2 10             5               7

2 5

2*2*2*5      3*5      3*7

We can find no common factor. So H.C.F. is 1 and L.C.M. is 420.

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