2. Sample Papers
  3. NTSE

NTSE Sample Paper NTSE SAT Practice Test-15

  • question_answer
                       If \[{{x}^{a}}={{y}^{b}}={{z}^{c}}\] and \[{{y}^{2}}=zx\]then which of the following is true?                                  

    A) \[a+c=2b\]                   

    B) \[{{b}^{2}}=ac\]

    C) \[\frac{1}{a}+\frac{1}{c}=\frac{2}{b}\]            

    D) \[{{a}^{2}}+{{c}^{2}}=2{{b}^{2}}\]

    Correct Answer: C

    Solution :

    [c] \[{{x}^{a}}={{y}^{b}}={{z}^{c}}=k\,(say)\] \[\Rightarrow \,\,x={{k}^{\frac{1}{a}}},y={{k}^{\frac{1}{b}}},z={{k}^{\frac{1}{c}}}\]             \[{{y}^{2}}=zx\Rightarrow {{k}^{2/b}}={{k}^{1/c}}.{{k}^{1/a}}\]             \[\Rightarrow \frac{2}{b}=\frac{1}{a}+\frac{1}{c}\]       


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