Question

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)%​

Answer 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 %