Let 1st number be F Then middle and largest = F + 2, and F + 4, respectively We then get: 5(F + 2) = F + F + 4 + 495 5F + 10 = 2F + 499 5F - 2F = 499 - 10 3F = 489 F, or 1st = You should be able to find the middle and largest!