NO.PZ2018062017000005
问题如下：
The demand function for orange is given by the equation:
(Q0)=80-3(P0)+0.1I+0.5(P1)
(Q0 is the quantity of orange demanded, P0 is the price of orange, I is the income, P1 is the price of apple)
We know that P0=30,I=110,P1=20. The cross-price elasticity of demand for apple with above information will be :
选项：
A.0.6
B.0.9
C.–0.4
解释：
B is correct.
From the demand function equation:
d Q0 / d P0=0.5
Q0=80-3(30)+0.1(110)+0.5(20)=11
When P1=20, the cross-price elasticity of demand will be 0.5(20/11)=0.9
考点：Cross Elasticity
解析：依据需求函数可得，d Q0 / d P0=0.5
把条件里的数值带入公式得：Q0=80-3(30)+0.1(110)+0.5(20)=11
当 P1=20时, 商品的交叉价格弹性= 0.5(20/11)=0.9
解析
B is correct.
From the demand function equation:
d Q0 / d P0=0.5
Q0=80-3(30)+0.1(110)+0.5(20)=11
When P1=20, the cross-price elasticity of demand will be 0.5(20/11)=0.9
考点：Cross Elasticity
解析：依据需求函数可得，d Q0 / d P0=0.5
把条件里的数值带入公式得：Q0=80-3(30)+0.1(110)+0.5(20)=11
当 P1=20时, 商品的交叉价格弹性= 0.5(20/11)=0.9
