What are 3 consecutive multiplies of 9 that add up to 243?

Answer 1

Suppose 9*(n-1) + 9*n + 9*(n+1) = 243

then dividing by n, (n-1) + n + (n+1) = 243/9 = 27

that is, 3n = 27 and so n = 9

So the three numbers are 9*8, 9*9 and 9*10 ie 72, 81 and 90.