The difference of compound interest and simple interest for 3 years and for 2 years are in ratio 23 : 7 respectively. What is rate of interest per annum (in %)?
1). 200/7
2). 100/7
3). 300/7
4). 400/7
⇒ (CI – SI)3/(CI – SI)2 = [P(R/100)2 × (300 + R)/100]/ P(R/100)2 = 23/7
⇒ (CI – SI)3/(CI – SI)2 = (300 + R)/100 = 23/7
⇒ (CI – SI)3/(CI – SI)2 = 2100 + 7R = 2300
⇒ 7R = 200
∴ R = 200/7
8. The simple interest at x% for x years will be Rs. x on a sum of: