Find the 8th term of below series: 2+i, 3+i, 5+2i, 7+3i, 11+5i, ...

M4maths Previous Puzzles

10 Apr 2017 Series

Find the 8th term of below series:
2+i, 3+i, 5+2i, 7+3i, 11+5i, ...

OPtion

1) 13+7i
2) 14+7i
3) 13+8i
4) 17+8i
5) 17+13i
6) 13+13i
7) 19+21i
8) 19+13i
9) 17+21i
10) None of these

Solution

Answer: 19+21i

Each element of series can be represented as a and ib where
a(n) = nth prime number
ib(n) = nth Fibonacci number

8th prime number when first term is 2 = 19
8th Fibonacci number when first number is 1 = 21

Hence 8th term = 19+21i
Option 7)

Correct Option: 7 Best Solution (4)