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Q.

The least common multiple of two natural numbers $a$ and $b$, is 399.

What is the minimum possible sum of the digits of the number a(given $a > b$)?

 A.

1

 B.

3

 C.

5

 D.

7

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Solution:
Option(B) is correct

Factorize $399 = 3×7×19$
The possible pairs are: $(57,7), (21,19), (399,1), (133,3)$

The least possible sum is given when $a =21 \text{ and }b =19$
And the sum is $2+1 =3$


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