A sum of money doubles itself in 10 years at simple interest. What is the rate…
2019
A sum of money doubles itself in 10 years at simple interest. What is the rate of interest?
- A.
10%
- B.
2%
- C.
5%
- D.
8%
Attempted by 47 students.
Show answer & explanation
Correct answer: A
Let the principal be P. Since the amount doubles, the simple interest (SI) earned is P.
Using the formula for simple interest: SI = (P × R × T)/100, where R is the rate and T is time in years.
Substitute SI = P and T = 10: P = (P × R × 10)/100.
Cancel P from both sides: 1 = (R × 10)/100.
Solve for R: R = 100/10 = 10%.
हिन्दी उत्तर: माना मूलधन P है। चूँकि राशि दोगुनी हो जाती है, तो साधारण ब्याज (SI) = P होगा।
साधारण ब्याज के सूत्र का उपयोग करें: SI = (P × R × T)/100, जहाँ R दर और T वर्षों में समय है।
SI = P और T = 10 रखने पर: P = (P × R × 10)/100।
दोनों तरफ P को काटें: 1 = (R × 10)/100।
R के लिए हल करें: R = 100/10 = 10%।