If the arithmetic mean of two numbers a and b ,   a > b > 0 , is five times their geometric…

If the arithmetic mean of two numbers a and b, a>b>0 , is five times their geometric mean, then a+ba-b is equal to:

  1. 7312
  2. 324
  3. 62
  4. 5612

Solution

Arithmetic Mean =a+b2
Geometric Mean =ab

a+b2=5ab
a+b=10ab

(a+b)2=100ab

(a-b)2=(a+b)2-4ab=96ab

Now,

a+ba-b=(a+b)2(a-b)2=10096

=5612

Asked in: JEE Main 2017 (08 Apr Online)

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