The difference between CI and SI on a certain sum of money for 3 years at 5% p.a. is Rs. 122. Find the sum invested = ?
A. Rs. 10000
B. Rs. 12000
C. Rs. 16000
D. Rs. 20000
Answer: Option C
Solution(By Examveda Team)
$$\eqalign{ & {\text{Rate of interest = 5}}\% {\text{ p}}{\text{.c}}{\text{.p}}{\text{.a}}{\text{.}} \cr & {\text{If time 3 years than CI}} - {\text{SI}} \cr & {\text{ = }}P\left[ {{{\left( {\frac{R}{{100}}} \right)}^3} + 3{{\left( {\frac{R}{{100}}} \right)}^2}} \right] \cr & \Rightarrow 122 = P\left[ {{{\left( {\frac{5}{{100}}} \right)}^3} + 3{{\left( {\frac{5}{{100}}} \right)}^2}} \right] \cr & \Rightarrow 122 = P\left( {\frac{{125}}{{1000000}} + \frac{{75}}{{10000}}} \right) \cr & \Rightarrow 122 = P\left[ {\frac{{125 + 7500}}{{1000000}}} \right] \cr & \Rightarrow 122 = P\left[ {\frac{{7525}}{{1000000}}} \right] \cr & \Rightarrow P = \frac{{122 \times 1000000}}{{7625}} \cr & \Rightarrow P = {\text{Rs}}{\text{. 16000}} \cr} $$Related Questions on Compound Interest
A. Rs. 120
B. Rs. 121
C. Rs. 122
D. Rs. 123
E. None of these
A. 625
B. 630
C. 640
D. 650
E. None of these
A. Rs. 2160
B. Rs. 3120
C. Rs. 3972
D. Rs. 6240
E. None of these
A. Rs. 2.04
B. Rs. 3.06
C. Rs. 4.80
D. Rs. 8.30
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