Without building the entire pyramid, find the number in the topmost row given the bottom row in each of these cases. Class 8
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Without building the entire pyramid, find the number in the topmost row given the bottom row in each of these cases. Class 8
Question 1.
Without building the entire pyramid, find the number in the topmost row given the bottom row in each of these cases.
Recall the Virahanka-Fibonacci number sequence 1, 2, 3, 5, ... where each number is the sum of the two numbers before it. Class 8
Solution:
(i) 8 + 3 × 9 + 3 × 21 + 13
= 8 + 27 + 63 + 13 = 111.
(ii) 7 + 3 × 18 + 3 × 19 + 6
= 7 + 54 + 57 + 6 = 124.
(iii) 9 + 3 × 7 + 3 × 5 + 11
= 9 + 21 + 15 + 11 = 56.
Question 2.
If the first three Virahanka-Fibo¬nacci numbers are written in the bottom row of a number pyramid with three rows, fill in the rest of the pyramid. What numbers appear in the grid? What is the number at the top? Are they all Virahanka-Fibonacci numbers? Class 8
Solution:
Yes.