Multiple choice

A sum at certain rate of compound interest become 600 in 8 years and become 900 at the end of 16 years. Find the amount after 20 years? एक राशि एक निश्चित चक्रवृद्धि ब्याज की दर से 8 वर्षों में 600 तथा 16 वर्षों में 900 हो जाती है। 20 वर्षों के पश्चात मिश्रधन ज्ञात कीजिये ?

  1. Rs. 1625

  2. Rs. 1225

  3. Rs. 1125

  4. Rs. 5625
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let P be principal and rate be r%. From the data: P(1+r)^8 = 600 and P(1+r)^16 = 900. Dividing gives (1+r)^8 = 3/2. So P = 600/(3/2) = 400. Amount after 20 years = 400 × (3/2)^(20/8) = 400 × (3/2)^2.5 ≈ 1125 (closest option). The calculation involves fractional exponents which are approximated in exam settings.

Keep practicing — related questions