11) If the simple interest on a sum of money for 2 years at 5% per annum is Rs.50, what will be the compound interest on same val
- 1) Rs.51.75
- 2) Rs 51.50
- 3) Rs 51.25
- 4) Rs 51
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View Explanation
Ans. C
Explanation :
\begin{aligned}
S.I. = \frac{P*R*T}{100} \\
P = \frac{50*100}{5*2} = 500\
Amount = 500(1+\frac{5}{100})^2 \500(\frac{21}{20} * \frac{21}{20}) \= 551.25 \
C.I. = 551.25 - 500 = 51.25
\end{aligned}
12) What will be the difference between simple and compound interest @ 10% per annum on the sum of Rs 1000 after 4 ye
- 1) Rs 62.10
- 2) Rs 63.10
- 3) Rs 64.10
- 4) Rs 65.10
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View Explanation
Ans. C
Explanation :
\begin{aligned}
S.I. = \frac{1000*10*4}{100} = 400 \C.I. = [1000(1+\frac{10}{100})^4 - 1000] \= 464.10
\end{aligned}
So difference between simple interest and compound interest will be 464.10 - 400 = 64.10
13) The difference between simple and compound interests compounded annually on a certain sum of money for 2 years at 4% per annum is Rs 1. Find the
- 1) Rs 600
- 2) Rs 625
- 3) Rs 650
- 4) Rs 675
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View Explanation
Ans. B
Explanation :
Let the Sum be P
\begin{aligned}
S.I. = \frac{P*4*2}{100} = \frac{2P}{25}\
C.I. = P(1+\frac{4}{100})^2 - P \
= \frac{676P}{625} - P \= \frac{51P}{625} \\text{As, C.I. - S.I = 1}\=> \frac{51P}{625} - \frac{2P}{25} = 1 \=> \frac{51P - 50P}{625} = 1 \P = 625
\end{aligned}
14) Simple interest on a certain sum of money for 3 years at 8% per annum is half the compound interest on Rs. 4000 for 2 years at 10% per annum. The sum placed on simple interest
- 1) Rs 1650
- 2) Rs 1750
- 3) Rs 1850
- 4) Rs 1950
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View Explanation
Ans. B
Explanation :
\begin{aligned}
C.I. = (4000 \times(1+\frac{10}{100})^2 - 4000) \= 4000 * \frac{11}{10} * \frac{11}{10} - 4000 \= 840 \
\text{So S.I. = } \frac{840}{2} = 420\
\text{So Sum = } \frac{S.I. * 100}{R*T} \= \frac{420 * 100}{3*8} \= Rs 1750
\end{aligned}