SSC Sample Paper SSC CHSL (10+2) Sample Test Paper-23

  • question_answer
    A certain sum becomes Rs. 2700 in two years and Rs.2900 in 4 years on. Find the principle and rate

    A)  \[2000,5%\]     

    B)  \[3000,4%.\]

    C)  \[2500,5%\]     

    D)  \[~2500,4%\]

    Correct Answer: D

    Solution :

     Let the principal = P and rate = r \[\therefore \]   SI after 2 years \[\frac{P\times r\times 2}{100}=\frac{P\times r}{50}\] \[\therefore \] Amount  \[=P+\frac{P\times r}{50}=2700\] \[\therefore \,\,\,\,\frac{\Pr }{50}=2700-P\] \[\therefore \,\,\,\,\Pr =50\,(2700-p)\]            ?..(i) SI after 4 years \[=\frac{P\times r\times 4}{100}=\frac{\Pr }{25}\] \[\therefore \]  Amount- \[P+\frac{\Pr }{25}=2900\] \[\therefore \,\,\,\,\frac{\Pr }{25}=2900-P\] \[\Rightarrow \,\,\,\Pr =25\,(2900-P)\]                   ?..(ii) Comparing equation (i) and (ii)- \[50(2700-P)=25(2900-P)\] \[2(2700-P)\,=2900-P\] \[5400-2P=2900-P\] \[5400-2900=-P+2P\Rightarrow \underline{\mathbf{P=2500}}\] \[\therefore \]   Rate  \[=\frac{SI\times 100}{P\times t}\] SI \[=2700-2500=200\] \[\therefore \] Rate \[=\frac{200\times 100}{2500\times 2}=\underline{\mathbf{4%}}\]


You need to login to perform this action.
You will be redirected in 3 sec spinner