In march, Jaka received a voucher worth Rp$500,000$ which could be used to buy grilled chicken or grilled fish at the campus cafeteria. The voucher could

not be used to purchase other dishes. Any remaining amount in the voucher could not be used beyond march. That month, the price of grilled chicken

was Rp$25,000$ per portion and grilled fish was Rp$20,000$ per portion. Jaka purchased $12$ portions of grilled chicken and $10$ portions of grilled fish.

Jaka received a similar voucher this month, but the price of grilled fish has increased to Rp$25,000$ per portion. Jaka decides to buy $15$ portions of grilled

chicken and $5$ portions of grilled fish.

i$.$ Illustrate graphically Jaka's purchases last month and this month, clearly showing the substitution effect, income effect, and total effect on the graph.

ii $.$ What type of good is grilled fish for Jaka?

iii. Derive Jaka's demand curve for grilled fish.

Please solve using equations and graphs.

#Microeconomics