Department of Economics
Dr. Shahar Sansani
University of California, Davis
Winter Quarter - 2021
Honor Pledge:
1)
I affirm that I will not give or receive any unauthorized help from anyone on this exam, and
that all work is my own.
2)
I understand that acts of academic dishonesty will be reported to the Office of Student
Support and Judicial Affairs.
Name (print): _________________________________________________
Signature:
___________________________________________________
Date: ________________
1

Department of Economics
Dr. Shahar Sansani
University of California, Davis
Winter Quarter - 2021
Midterm #1 – February 9, 2021
Name:________________________
ECN 100A – Intermediate Microeconomics
---------------------------------------------------------------------------------------------------------------------
**Note that correct answers without adequate work shown will receive little to no credit**
1) Suppose Roma tomatoes (x
1
) and Cherry tomatoes (x
2
) are perfect substitutes for Vince.
Vince is always willing to trade 4 Cherry tomatoes for 1 Roma tomato.
a) What is a possibility for Vince’s utility function? (4 points)

b) Suppose that Roma tomatoes cost $1 per tomato and Cherry tomatoes cost $0.20 per
tomato. However, the store selling Cherry tomatoes requires a membership fee. If Vince’s
income is $40, what is the most he is willing to pay for the membership fee? (Hint: recall that
we assume consumers always choose whatever will yield them the highest utility) (8 points)

2) Suppose Patrick’s utility function is u(x
1
, x
2
) = x
1
+ 210*ln (x
2
). The price of x
1
is $1 and the
price of x
2
is $1. If we know that Patrick’s optimal bundle includes 200 units of x
2
, what is his
income? (Hint: The partial derivative of x
2
is (210/x
2
)) (12 points)

3) Suppose John buys only oranges (x
1
) and bananas (x
2
). He spent $24 on snacks last week
when oranges cost $3/lb. and bananas cost $3/lb. John decided to buy 2 lbs. of oranges and 6
lbs. of bananas.