10. If 50% of (x- y) = 40% of (x + y), then what percent of x is y?
(a) 10(1/9)% (b) 11(1/9)% (c) 13(1/9)% (d) 21(1/9)%​

1 thought on “10. If 50% of (x- y) = 40% of (x + y), then what percent of x is y?<br />(a) 10(1/9)% (b) 11(1/9)% (c) 13(1/9)% (d) 21(1/9)%​”

1. Answer:

   Option (b)

   Step-by-step explanation:

   Given:–

   50% of (x- y) = 40% of (x + y)

   To find:–

   If 50% of (x- y) = 40% of (x + y), then what percent of x is y?

   Solution:–

   Given that

   50% of (x- y) = 40% of (x + y)

   =>50% × (x- y) = 40% ×(x + y)

   =>(50/100)× (x- y) = (40/100)× (x + y)

   = (1/2)×(x- y) = (2/5)× (x + y)

   =>(x -y)/2 = 2(x + y)/5

   =>(x-y)/2 = (2x+2y)/5

   On applying cross multiplication then

   =>5(x-y) = 2(2x+2y)

   =>5x -5y = 4x +4y

   =>5x -4x = 4y +5y

   =>x = 9y —–(1)

   Let A% of x = y

   =>A% ×x = y

   =>(A/100)× x = y

   =>A×9y/100 = y

   =>A9y/100 = y

   On cancelling y both sides

   =>9A /100 = 1

   =>9A = 1×100

   =>9A = 100

   =>A = 100/9%

   =>A = 11 1/9 %

   Answer:–

   The required percentage for the given problem is

   11 1/9 %

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