📢 Too many exams? Don’t know which one suits you best? Book Your Free Expert 👉 call Now!
  • google app store apple app store
    • ✖

      Question

      The sum of the areas of two circles P and Q is 20020

      cm2. If the product of the diameters of both circles P and Q is 12348 cm, then find out the sum of the radius of both of the circles.
      A 112 cm Correct Answer Incorrect Answer
      B 128 cm Correct Answer Incorrect Answer
      C 96 cm Correct Answer Incorrect Answer
      D 104 cm Correct Answer Incorrect Answer
      E None of the above Correct Answer Incorrect Answer

      Solution

      Let’s assume the radius of circles P and Q are ‘R’ and ‘r’.

      The sum of the areas of two circles P and Q is 20020 cm2.

      πxR2 + πxr2  = 20020

      π(R2  + r2 ) = 20020

      22/7(R2  + r2 ) = 20020

      (R2 + r2 ) = 20020x(7/22)

      (R2  + r2 ) = 6370    Eq.(i)

      If the product of the diameters of both circles P and Q is 12348 cm.

      2Rx2r = 12348

      4Rr = 12348

      2Rr = 6174    Eq.(ii)

      Sum of the radius of both of the circles = (R+r)

      Make a square with the help of a formula.

      (R+r)2  = R2 +r2 +2Rr

      Put Eq.(i) and Eq.(ii) in the above equation.

      (R+r)2  = 6370+6174

      (R+r)2  = 6370+6174 = 12544

      So the sum of the radius of both of the circles = (R+r) = 112 cm

      Practice Next
      More Mensuration Questions
      ask-question