Two numbers are in the ratio 3 :7. If their L.C.M. is 189. What is the sum of the numbers?

Answer 1

90

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a/b=3/7
LCM=189
a+b=?

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We know that a*b=LCM*HCM
If HCM is x, then 3x*7x=189x --> x=9
a*b=3*7*9*9
a/b=3/7
a=3*9=27, b=7*9=63, a+b=90