8 kyu
link to kata
my solution
Find the sum of all multiples of n below m
Keep in Mind
n and m are natural numbers (positive integers) m is excluded from the multiples Examples
sumMul(2, 9) ==> 2 + 4 + 6 + 8 = 20
sumMul(3, 13) ==> 3 + 6 + 9 + 12 = 30
sumMul(4, 123) ==> 4 + 8 + 12 + ... = 1860
sumMul(4, -7) ==> "INVALID"