Subtopic: Fundamentals of Biomolecules, enzyme kinetics
Question Statement:
A series (S) is given as
S = 1 + 3 + 5 + 7 + 9 + ……
The sum of the first 50 terms of S is ____________.
Official Answer Key:
2500 to 2500
Step-by-Step Solution & Explanation
### **Step-by-Step Solution & Mathematical Derivation (GATE BT 2023 Q.32)**
**1. Governing Concept & Definition**:
- **Topic**: General Aptitude & Sum of Arithmetic Progression
- The given series $S = 1 + 3 + 5 + 7 + 9 + \dots$ is the sequence of consecutive odd natural numbers.
- For an AP with first term $a = 1$ and common difference $d = 2$, the sum of the first $n$ odd positive integers is:
$S_n = n^2$
**2. Detailed Step-by-Step Calculation**:
- **Given**:
- Number of terms $n = 50$
- First term $a = 1$
- Common difference $d = 2$
- **Standard AP Sum Formula**:
$S_n = \frac{n}{2} [2a + (n - 1)d] = \frac{50}{2} [2(1) + (50 - 1)(2)] = 25 \times [2 + 98] = 25 \times 100 = 2500$
- Or directly:
$S_{50} = 50^2 = 2500$
**3. Final Answer**:
- **Calculated Value**: **2500**
- **Official GATE Accepted Range**: **2500 to 2500**
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