If a sequence is a given below:
1,1,2,3,5,8,13,21,34, ....
In the above sequence the 55th term will be :

Options

A. an even number
B. an odd number
C. either even or odd
D. can't be determined

Answer

To find the 55th term in the given sequence, we first need to identify the pattern in the sequence. The sequence provided is:

1, 1, 2, 3, 5, 8, 13, 21, 34, ...

This sequence is known as the Fibonacci sequence, where each term is the sum of the two preceding terms.

### Step-by-Step Solution:

1. **Identify the Fibonacci Sequence**:
The Fibonacci sequence starts with 1, 1, and each subsequent term is the sum of the two previous terms:
- 1st term: 1
- 2nd term: 1
- 3rd term: 1 + 1 = 2
- 4th term: 1 + 2 = 3
- 5th term: 2 + 3 = 5
- 6th term: 3 + 5 = 8
- 7th term: 5 + 8 = 13
- 8th term: 8 + 13 = 21
- 9th term: 13 + 21 = 34
- 10th term: 21 + 34 = 55
- 11th term: 34 + 55 = 89
- and so on...

2. **Calculate the 55th Term**:
To find the 55th term, we can either continue calculating the terms until we reach the 55th or use a formula. The nth term of the Fibonacci sequence can be calculated using Binet's formula, but for practical purposes, we can compute it iteratively or recursively.

3. **Iterative Calculation**:
We can compute the Fibonacci numbers iteratively until we reach the 55th term:
- Initialize the first two terms: `a = 1`, `b = 1`
- For each term from 3 to 55, update `a` and `b`:
```
for i from 3 to 55:
c = a + b
a = b
b = c
```
- After the loop, `b` will hold the value of the 55th term.

4. **Final Result**:
After performing the calculations, we find that the 55th term in the Fibonacci sequence is **139583862445**.