SSC Sample Paper Mock Test-9 SSC CGL Tear-II Paper-1

  • question_answer
    The sum and product of two numbers are 10 and 24 respectively. The sum of their reciprocals is

    A)  \[\frac{1}{2}\] 

    B)  \[\frac{5}{12}\]

    C)  \[\frac{7}{12}\]

    D)  \[\frac{12}{5}\]

    Correct Answer: B

    Solution :

    Let the numbers be x and y, respectively.
    \[x+y=10\]                                ?(i)
    \[xy=24\]
    \[{{(x-y)}^{2}}={{(x+y)}^{2}}-4xy\]
    \[=100-4\times 24=4\]
    \[\Rightarrow \]   \[x-y=2\]                                   ...(ii)
    On adding Eqs. (i) and (ii), we get
    \[x+y=10\]
    \[x-y=2\]
    \[2x=12\]\[\Rightarrow \]\[x=6\]
    From Eq. (i), y = 4
    Sum of reciprocals \[=\frac{1}{6}+\frac{1}{4}=\frac{2+3}{12}=\frac{5}{12}\]


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