Micro doubt

[Anjali]

An individual always consumes good x and y in the fixed proportion of 2:1 . If the price of x is Rs 10/unit and of y Rs 5/unit , compute price elasticity of demand of x .

[Homer Simpson]

hey, i got (-Px/Px+2.5) but i am not very sure about this!

[Dreyfus]

The utility function is min{x/2,y}
So demand func for x = 2m/(2px+py)
dx/dpx=-4m/(2px+py)^2
ed=-0.8

[Anjali]

Vaibhav m getting -0.4 !

[Dreyfus]

Check ur calculations again! I m getting -0.8 only

[Anjali]

M getting -4m/ (2px + Py ) ^2
Now
Px X + Py Y = m
2Px X + X Py = 2 m
25 X = 2m
Substituting this value :
{- 2 * 25 X / ( 2px + Py ) ^ 2 } * Px / X
[- 2 * 25 / 25 * 25 ] * 10
= -0.8
Yippee , got it !
Is my approach fine ?