Math question to find out X and Y

Question

If

( 90% × 10 ) + ( 10% × 5 ) = 9.5

What is the formula to find out each X and Y in the below

( 90% × X ) + ( 10% × Y ) = 2

Answer 1

.9x10 + .1x5 = 9 +.5 = 9.5

where X=10, Y=5 or X=2Y and Y=X/2

if .9X + .1Y = 2,

then X=(2/9.5)10 = (4/19)10

X= 40/19

and Y=X/2 = 20/19