Compound Interest
- The compound interest on ₹ 2000 in 2 years if the rate of interest is 4% per annum for the first year and 3% per annum for the second year, will be
-
View Hint View Answer Discuss in Forum
Given Here , R1 = 4% , R2 = 3% , P = ₹ 2000
Using formula ,Amount = P 
1 + R1 
1 + R2 100 100 Amount = 2000 1 + 4 1 + 3 100 100
Correct Option: A
Given Here , R1 = 4% , R2 = 3% , P = ₹ 2000
Using formula ,Amount = P 1 + R1 1 + R2 100 100 Amount = 2000 1 + 4 1 + 3 100 100
Amount = 2000 × 1.04 × 1.03 = ₹ 2142.40
∴ CI = Amount - Principal
∴ CI = ₹ (2142.40 – 2000) = ₹ 142.40
- If the rate of interest be 4% per annum for first year, 5% per annum for second year and 6% per annum for third year, then the compound interest of ₹ 10,000 for 3 years will be
-
View Hint View Answer Discuss in Forum
Given that , R1 = 4% , R2 = 5% , R3 = 6% , P = ₹ 10,000
Using the given formula ,Amount = P 1 + R1 1 + R2 1 + R3 100 100 100 Amount = 10000 1 + 4 1 + 5 1 + 6 100 100 100
Correct Option: C
Given that , R1 = 4% , R2 = 5% , R3 = 6% , P = ₹ 10,000
Using the given formula ,Amount = P 1 + R1 1 + R2 1 + R3 100 100 100 Amount = 10000 1 + 4 1 + 5 1 + 6 100 100 100 Amount = 10000 × 26 × 21 × 53 = ₹ 11575.2 25 20 50
∴ C.I. = Amount - Principal
∴ C.I. = ₹ (11575.2 – 10000) = ₹ 1575.2
- The compound interest on ₹ 16,000 for 9 months at 20% per annum, interest being compounded quarterly, is
-
View Hint View Answer Discuss in Forum
The interest is compounded quarterly.
∴ R = 20 = 5% 4
Time = 3 quarters , P = ₹ 16,000∴ C.I. = P 
1 + R T − 1 
100 C.I. = 16000 1 + 5 3 − 1 100 C.I. = 16000 21 3 − 1 20
Correct Option: C
The interest is compounded quarterly.
∴ R = 20 = 5% 4
Time = 3 quarters , P = ₹ 16,000∴ C.I. = P 1 + R T − 1 100 C.I. = 16000 1 + 5 3 − 1 100 C.I. = 16000 21 3 − 1 20 C.I. = 16000 9261 − 8000 8000 C.I. = 16000 × 1261 = ₹ 2522 8000
- The compound interest on a sum of money for 2 years is ₹ 615 and the simple interest for the same period is ₹ 600. Find the principal.
-
View Hint View Answer Discuss in Forum
Given that , compound interest ( C.I. ) = ₹ 615 , simple interest ( S.I. ) = ₹ 600 , Time = 2 years
∴ C.I. – S.I. = 615 – 600 = ₹ 15S.I. for 1 year = 600 = ₹ 300 2
∴ S.I. for 1 year on ₹ 300 = ₹ 15∴ Rate = 15 × 100 = 5% 300 × 1
Correct Option: B
Given that , compound interest ( C.I. ) = ₹ 615 , simple interest ( S.I. ) = ₹ 600 , Time = 2 years
∴ C.I. – S.I. = 615 – 600 = ₹ 15S.I. for 1 year = 600 = ₹ 300 2
∴ S.I. for 1 year on ₹ 300 = ₹ 15∴ Rate = 15 × 100 = 5% 300 × 1
As we know that ,∴ PRT = 600 100 ⇒ P × 5 × 2 = 600 100
⇒ P = 600 × 10 = ₹ 6000
- The compound interest on Rs. 30,000 at 7% per annum for n years is Rs. 4347. The value of n is
-
View Hint View Answer Discuss in Forum
Here , Principal = Rs. 30000 , CI = Rs. 4347 , Rate = 7% , Time = n years
Amount = Principal + CI = Rs. (30000 + 4347) = Rs. 34347
Using the given formula ,A = P 
1 + R T 100 ⇒ 34347 = 30000 1 + 7 n 100 ⇒ 34347 = 107 n 30000 100 ⇒ 11449 = 107 n 10000 100
Correct Option: B
Here , Principal = Rs. 30000 , CI = Rs. 4347 , Rate = 7% , Time = n years
Amount = Principal + CI = Rs. (30000 + 4347) = Rs. 34347
Using the given formula ,A = P 1 + R T 100 ⇒ 34347 = 30000 1 + 7 n 100 ⇒ 34347 = 107 n 30000 100 ⇒ 11449 = 107 n 10000 100 ⇒ 107 2 = 107 n 100 100
On equating powers both sides ,
⇒ n = 2 years
