Question

The difference between simple interest and compound interest on a certain sum of money for 3 years at 5% per annum is Rs. 122. Find the sum

• A. Rs. 12,200
• B. Rs. 15,000
• C. Rs. 16,500
• D. Rs. 16,000

Answer 1

Answer: (D)

Rs. 16,000

Suppose $sum=P$
Given $CI-SI=Rs.122$
$P{(1+\frac{5}{100})}^3-P-\left(\frac{P\times 5\times 3}{100}\right)=122$
$P(\frac{{105}^3}{{100}^3}-1-\frac{15}{100})=122$
$P\left(\frac{7,625}{{100}^3}\right)=122$
$P=\frac{122\times {100}^3}{7,625}=Rs.16,000$