A sum of Rs. 4800 is invested at compound interest for 3 years. What is the amount? A. Rs. 2520 B. Rs. 3120 C. Rs. 3320 D. Rs. 2760 Explanation: Apply the CI formula A = P(1+r)³.
Rs. 725 is lent at a certain rate. After 8 months, Rs. 362.50 more is lent at double the rate. Find the rate. A. 3.46% B. 4.5% C. 5% D. 6% Explanation: Equating interests gives a rate ≈ 3.46%.
A sum of Rs. 2500 amounts to Rs. 3875 in 4 years. Find the rate of simple interest. A. 12.25% B. 12% C. 6% D. 13.75% Explanation: SI = 1375 ⇒ rate = 13.75%.
A sum of Rs. 12,500 amounts to Rs. 15,500 in 4 years at simple interest. What is the rate? A. 3% B. 4% C. 5% D. 6% Explanation: SI = 3000 ⇒ rate = (3000×100)/(12500×4) = 6%.
A sum trebles itself in 15 years. In how many years will it double? A. 6 years 3 months B. 7 years 9 months C. 8 years 3 months D. 9 years 6 months Explanation: Using compound growth relation gives ≈ 7 years 9 months.
A sum doubles itself in 5 years at compound interest. In how many years will it become eight times? A. 7 years B. 10 years C. 15 years D. 20 years Explanation: 8 = 2³ ⇒ 3 × 5 = 15 years.
A sum doubles in 5 years. What will it amount to in 15 years? A. 7 times B. 10 times C. 15 times D. 20 times Explanation: Tripling period relation.
A sum doubles in 4 years. In how many years will it triple? A. 16 B. 8 C. 12 D. 20 Explanation: Using a compound growth relation.
A sum invested at 20% compound interest gives Rs. 482 extra in 2 years. Find principal. A. Rs. 4000 B. Rs. 1000 C. Rs. 1250 D. Rs. 2000 Explanation: Compound interest formula applied.
A sum is repaid in two equal installments with compound interest. What is principal? A. Rs. 1620 B. Rs. 1640 C. Rs. 1680 D. Rs. 1700 Explanation: Discounting installments gives the principal.