IBPS PO General Awareness: Simple Interest and Compound Interest questions with solutions

Q1. Calculate the rate of interest. (I) Pankaj earned Rs. 4500 as interest when he invested Rs. 6000. (II) Pankaj invested an equal amount in simple interest and compound interest. After 2 years, the compound interest received by Pankaj is Rs. 90 more than the simple interest received by Pankaj.

1. Statement (I) alone is sufficient to answer the question but statement (II) alone is not sufficient to answer the question.
2. Statement (II) alone is sufficient to answer the question but statement (I) alone is not sufficient to answer the question.
3. Both the statements taken together are necessary to answer the question, but neither of the statements alone is sufficient to answer the question.
4. Either statement (I) or statement (II) by itself is sufficient to answer the question.

Answer: Statement (II) alone is sufficient to answer the question but statement (I) alone is not sufficient to answer the question.

Statement I gives only the interest and principal, but not enough to uniquely determine the rate unless the time is known. Statement II gives the difference between CI and SI after 2 years, which is sufficient to find the rate using the standard formula for 2 years.

Q2. What is the rate of interest? I. Simple interest accrued on an amount of Rs. 25,000 in two years is less than the compound interest for the same period by Rs. 250. II. Simple interest accrued in 10 years is equal to the principal.

1. The data in Statement I alone is sufficient to answer the question, while the data in Statement II alone is not sufficient to answer the question.
2. The data in Statement II alone is sufficient to answer the question, while the data in Statement I alone is not sufficient to answer the question.
3. The data in Statement I alone or in Statement II alone are sufficient to answer the question.
4. The data in both the Statements I and II is not sufficient to answer the question.

Answer: The data in Statement I alone or in Statement II alone are sufficient to answer the question.

In Statement I, the difference between CI and SI for 2 years is enough to determine the rate using the formula for two-year compounding. In Statement II, if SI in 10 years equals the principal, then the rate is 10% per annum. Hence either statement alone is sufficient.

Q3. Divyam has ₹40,000. He invests some amount in Scheme A, which offers 30% per annum simple interest, and the rest of the amount in Scheme B, which offers 20% compound interest. If after three years, the interest received from Scheme A is ₹9,952 more than the interest received from Scheme B, then find the amount invested in Scheme B.

1. ₹24,000
2. ₹16,000
3. ₹12,000
4. ₹18,000

Answer: ₹16,000

Let the amount invested in Scheme B be x, so Scheme A gets 40000 - x. Scheme A earns simple interest at 30% for 3 years, and Scheme B earns compound interest at 20% for 3 years. Solving the difference equation gives x = 16000.

Q4. A sum of ₹20,500 is invested at 20% simple interest per annum for 4 years, and the amount obtained is then invested at 10% compound interest per annum for 2 years. Find the compound interest obtained.

1. 7997
2. 7479
3. 7974
4. 7749

Answer: 7749

The first investment grows by simple interest for 4 years, giving a new amount. That amount is then compounded at 10% for 2 years, and the compound interest is the excess over that second principal. Carrying out both stages gives ₹7,749.

Q5. A man invested ₹5P in scheme X earning simple interest at (R - 4)% per annum. After 4 years, the amount becomes ₹7.4P. He gives 60% of what he invested to his friend. His friend invests this money in scheme Y for 3 years, earning compound interest at \((R/2 + 7)%\) per annum. The difference between the simple interest and compound interest earned is ₹2679.60. Find the money invested in scheme X.

1. ₹9600
2. ₹16000
3. ₹12800
4. ₹15000

Answer: ₹16000

From ₹5P to ₹7.4P in 4 years, the simple interest is ₹2.4P, so the annual rate in scheme X can be found. Using that rate, the rate in scheme Y is determined, and comparing the simple interest from scheme X with the compound interest from scheme Y gives the value of P. Substituting yields the invested amount as ₹16000.