18 and 81
256
12(6 + 5)
25 and 18 are a factor pair of 450 whose sum is 43.
16 and 12
Since one number is twice the other, the smaller number must be the greatest common factor. Since the greatest common factor is 7, that would make the other number 14. But, 7 is a prime number and has only one prime factor. However, the larger number, 14, has two prime factors. Also, the sum of the two numbers is 21, not 105. So, the information in the problem does not have a solution. Let us ignore the greatest common factor information. Let the smaller number be x. That means the larger number is 2x. x + 2x = 105 => 3x = 105 => x = 35. The two numbers are 35 and 70. The greatest common factor is 35. The smaller number, 35, has only two prime factors.
27 and 36
Answer: 276
Their greatest common factor is 27
15 x 11
336 and 48
W(1 + 1)
90 and 9