JMO

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)?




Answer:

the factors of 399 are 3, 7 and 19

so, the possible numbers are (399,1), (133, 3), (21, 19), (57, 7)

So, the min. possible sum of digits = 2 + 1 = 3