The greatest common divisor of two natural numbers is 18, and the least common multiple is 108,
Let two numbers be a and B respectively, a = greatest common divisor * C, B = greatest common divisor * D, and C and D are coprime. The least common multiple = greatest common divisor * c * D. so c * d = 108 / 18 = 6 = 2 * 3, that is, C and D are 2 and 3, so the two numbers are 18 * 2 = 36, 18 * 3 = 54, and the sum of two numbers is 36 + 54 = 90