Answer:
Fibonacci sequence or Fibonacci numbers are a group of number/terms in which each number is the sum of the two preceding ones. This goes as follows:
0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ... ,∞
Fib(1) + Fib(2) + Fib(3) + Fib(4) + Fib(5) = ?
= 1 + 1 + 2 + 3 + 5 (because the first term (0) is written as Fib(0).)
= 12
Hope this helps. ^^
