Question:
A sum of money invested at simple interest amounts to Rs. 8,800 in 3 years and to Rs. 10,400 in 5 years. What is the principal sum?
साधारण ब्याज पर निवेश की गई कोई धनराशि 3 वर्षों में 8,800 रुपये और 5 वर्षों में 10,400 रुपये हो जाती है। मूलधन कितना है?
Options:
- Rs. 6,400
- Rs. 6,000
- Rs. 7,200
- Rs. 6,800
- 6,400 रुपये
- 6,000 रुपये
- 7,200 रुपये
- 6,800 रुपये
Correct Answer: a)
Explanation:
Simple interest for 2 years (from year 3 to year 5) = \(10,400 – 8,800 = \text{Rs. } 1,600\).
Simple interest per year = \(1,600 / 2 = \text{Rs. } 800\).
Simple interest for 3 years = \(800 \times 3 = \text{Rs. } 2,400\).
Principal = Amount after 3 years – SI for 3 years = \(8,800 – 2,400 = \textbf{Rs. 6,400}\) (Option a).
2 वर्षों का साधारण ब्याज = \(10,400 – 8,800 = 1,600\) रुपये।
1 वर्ष का ब्याज = 800 रुपये।
3 वर्षों का ब्याज = \(800 \times 3 = 2,400\) रुपये।
मूलधन = \(8,800 – 2,400 = \textbf{6,400 रुपये}\) (विकल्प a)।