2. Sample Papers
  3. Railways

Railways Sample Paper RRB (Group D) Sample Test Paper-6

  • question_answer
    A sum of money at compound interest doubles itself in 15 years. It will become eight times of itself in

    A)  45 years

    B)  48 years

    C)  54 years          

    D)  60 years

    Correct Answer: A

    Solution :

    [a] \[A=P\,\,{{\left( 1+\frac{R}{100} \right)}^{T}}\] \[2=1\,\,{{\left( 1+\frac{Rate}{100} \right)}^{15}}\] Cubing on both sides, we have \[8=1\,\,{{\left( 1\frac{Rate}{100} \right)}^{45}}\] Required time = 45 years


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