a,b,c are positive integers forming an increasing G.P and b-a is a perfect cube and + + =6 then a+b+c=?
If a, b, and c form a geometric progression then b = ar and c = ar^2 (for some ratio r):
has to be a perfect cube, or has to be a perfect cube. There are a few possibilities for a (35, 28, 9), but the only one that will work in our case is if a = 9.
If a = 9 and b = 36, then r = 4, which makes c = 144. So a + b + c = 189.