The correct option is A
The missing number is 34
By inspection, the third number is obtained by adding the two preceding numbers.
1 + 1 = 2
The next number is obtained by adding the two preceding numbers.
2 + 1 = 3
This continues as:
3 + 2 = 5
8 + 5 = 13
13 + 8 = 21
21 + 13 = 34
gcf = 3
the factors of 12 are 1, 2, 3, 4, 6 and 12
the factors of 45 are 1, 3, 5, 9, 15 and 45
the greatest common factor of 12 and 45 is 3
Answer:
The first one is 4
The second on is 21