Answer:
MUm/Pm = MUp/Pp [MU = marginal utility; p = plane ; m = milk ; P= Price]
Step-by-step explanation:
Consumer Equilibrium refers to consumer's utility maximising consumption , given prices & income.
Two Goods Case (Goods 1 &2): Equilibrium is where MU1 / P1= MU2 / P2
Here, two goods milk & plane : Equilibrium where MUm/Pm = MUp/Pp
If MUm/Pm > MUp/Pp : It means utility (satisfaction) of per unit money spent on milk is more than that of plane tickets. So, the consumer will tend to consumer more milk - this will reduce MU from milk [DMU law] , this will happen till falling MUm/Pm becomes = MUp/Pp
If MUp/Pp > MUm/Pm : It means utility (satisfaction) of per unit money spent on plane tickets is more than that of plane tickets. So, the consumer will tend to consumer more plane tickets - this will reduce MU from plane tickets [DMU law], this will happen till falling becomes MUp/Pp = MUm / Pm.