Multiple choice

A sum of money amounts to Rs.4840 in 2 years and to Rs.5324 in 3 years at compound interest compounded annually. The rate of interest per annum is- एक धनराशि चक्रवृद्धि ब्याज पर 2 वर्षों में रु.4840 और तीन वर्षों में रु.5324 हो जाती है जबकि वार्षिक ब्याज दर चक्रवृद्धि रूप से संयोजित होती है। वार्षिक ब्याज की दर है-

  1. 8%

  2. 9%

  3. 10%

  4. 11%

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

Let amount after 2 years = A = P(1 + r/100)² = 4840. After 3 years = P(1 + r/100)³ = 5324. Dividing: (1 + r/100) = 5324/4840 = 1.1. So r/100 = 0.1, r = 10%. Alternatively: Interest for 3rd year = 5324 - 4840 = Rs.484. This is the interest on Rs.4840 for 1 year. So r = (484/4840) × 100 = 10%.