2. Sample Papers
  3. Railways

Railways Sample Paper RRBs Assistant Loco Pilot and Technician CBT STAGE-I Sample Paper-20

  • question_answer
    If\[(x+y):(x-y)=7:3,\]then\[({{x}^{2}}+{{y}^{2}}):({{x}^{2}}-{{y}^{2}})\]is equal to

    A)  16 : 29

    B)  49 : 9

    C)  29 : 21

    D)  25 : 4

    Correct Answer: C

    Solution :

    Given, \[x+y=7\]                                               ?(i) \[x-y=3\]                                   ?(ii) After solving Eqs. (i) and (ii), we get \[\begin{align}   & x+y=7\,\,\,\,\,\,\,x-y=3 \\  & \frac{-\,\,\,\,+\,\,\,\,\,\,-}{\,\,\,\,\,2y=4} \\ \end{align}\] \[\therefore \] y= 2 and x=5 Now, \[({{x}^{2}}+{{y}^{2}}):({{x}^{2}}-{{y}^{2}})\] \[=[{{(5)}^{2}}+{{(2)}^{2}}]:[{{(5)}^{2}}-{{(2)}^{2}}]\] \[=(25+4):(25-4)=29:21\]


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