Like the fibonacci sequence 1, 1, 2, 3, 5, 8, . . . . a certain turkey flock has as many turkeys on a given day as the sum of the number of turkeys on the previous 2 days. If there were 79 turkeys on November 7th, and 542 turkeys on November 11th, how many turkeys were there on November 18th?
Choices:
A. 9,726
B. 15,737
C. 5,423
D. 25,463
Correct Answer: B
Solution:
Step 1: Let A be the number of turkeys on November 5th.
Step 2: Let B be the number of turkeys on November 6th.
Step 3: Given that the number of turkeys on a given day is the sum of the number of turkeys on the previous 2 days.
Step 4: Number of turkeys on November 7th = Number of turkeys on November 5th + Number of turkeys on November 6th.
Step 5: 
--------------- (1)
Step 6: Similarly the number of turkeys on November 8th = B + A + B = A + 2B
Step 7: Number of turkeys on November 9th = A + B + A + 2B = 2A + 3B
Step 8: Number of turkeys on November 10th = 2A +3B +A +3B = 3A + 5B
Step 9: Number of turkeys on November 11th = 2A + 3B + 3A + 5B = 5A + 8B
Step 10: 
------------(2)
Step 11: Solving equations (1) and (2)


____________
B = 49 then A = 30
Step 12: We get 30, 49, 79, 128, 207, 335, 542, 877,1419, 2296, 3715, 6011, 9726, 15737, .........
Step 13: Therefore, there are 15737 turkeys on November 18th.