Posted by Arnau on .
The ratio of three positive integers is 2:4:5 and their least common multiple is 300. What is the sum of the smallest and the largest of the three numbers?

Math (Algebra) 
Steve,
If the numbers are LCM(2x,4x,5x) = 20x
So, x=15. But 515, so use x=3 and the numbers are
30,60,75
30+75 = 105