Compound Interest Practice Test Set 3

Step 1: Identify what the question asks and note the relevant values from the question.
Step 2: Apply the appropriate compound-interest or simple-interest relationship.
A/P = 2,420 / 2,000 = 121 / 100 = (11/10)^2. Since rate is 10% (11/10 per year), the time period is 2 years.

Step 3: Match the calculated result with the options.
The matching value is the correct answer.

Correct Answer: Option C.

Step 1: Identify what the question asks and note the relevant values from the question.
Step 2: Apply the appropriate compound-interest or simple-interest relationship.
64 = $8^2$. Since it becomes 8 times in 3 years, it will become 8^2 = 64 times in 2 * 3 = 6 years.

Step 3: Match the calculated result with the options.
The matching value is the correct answer.

Correct Answer: Option D.

Step 1: Identify what the question asks and note the relevant values from the question.
Step 2: Apply the appropriate compound-interest or simple-interest relationship.
Amount A = 50,000 * 1.05 * 1.10 * 1.20 = 50,000 * 1.386 = Rs 69,300. CI = 69,300 - 50,000 = Rs 19,300.

Step 3: Match the calculated result with the options.
The matching value is the correct answer.

Correct Answer: Option A.

Step 1: Identify what the question asks and note the relevant values from the question.
Step 2: Apply the appropriate compound-interest or simple-interest relationship.
SI for 3 years at 8% = 24% = Rs 2,400 => Principal P = Rs 10,000. CI for 2 years at 10% = 21% of 10,000 = Rs 2,100.

Step 3: Match the calculated result with the options.
The matching value is the correct answer.

Correct Answer: Option B.

Step 1: Find the total amount.
Amount = Principal + Compound Interest = Rs 12,000 + Rs 1,891.50 = Rs 13,891.50.

Step 2: Calculate the amount-to-principal ratio.
A/P = 13,891.50 / 12,000 = 1.157625.

Step 3: Recognise the annual growth factor.
1.157625 = (1.$05)^3$. Therefore, the annual multiplier is 1.05.

Step 4: Calculate the rate.
Rate = (1.05 - 1) $\times 100 = 5% per annum$.

Correct Answer: 5%.

Correct Answer: Option C.