Multiple choice

A sum of money amount to Rs. 448 in 5 years and 550.40 in 9 years at certain rate of simple interest what is the sum? एक धनराशि किसी निश्चित ब्याज की दर से 5 वर्षों में 448रू. तथा 9 वर्षों में 550.40 रू. हो जाती है। मूलधन क्या होगा?

  1. 380

  2. 280

  3. 360

  4. 320

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let the principal be P and rate be R%. Amount after 5 years: P + (P×R×5)/100 = 448. Amount after 9 years: P + (P×R×9)/100 = 550.40. Subtracting: (P×R×4)/100 = 550.40 - 448 = 102.40. So PR/100 = 102.40/4 = 25.6. Substituting in first equation: P + 5×25.6 = 448, giving P = 448 - 128 = 320.