一道经济学的问题！！！

Question

Suppose that the supply of aged cheddar cheese is inelastic, and the supply of
bread is elastic. Both goods are considered to be normal goods by a majority of
consumers. Suppose that a large income tax increase decreases the demand for both
goods by 10%.
The price elasticity of supply for aged cheddar cheese could be
a) 0
b) 0.5
c) 1.5
d) -1
答案为什么是b啊？？

Answer 1

因为aged cheddar cheese的供给弹性是“inelastic”，所以是在[0,1)之间，但又是正常商品，所以也不可能是0。追问

所以不用考虑normal good这个条件么？

追答

“a large income tax increase decreases the demand for both goods by 10%”也能说明它是正常品了。

Answer 2

因为爱装逼