彈性題目 - 經濟

這是我們補習班老師發的考卷

其中有一題的答案我覺得很奇怪

所以想問問大家的意見

如有不妥 我會把它刪掉

題目如下:

When the price of bubble gum is $0.5,the quantity demanded is 400 packs per

day. When the price falls to $0.4,the quantity demanded increase to 600. given

this information and using minpoint method,you know that the demand for bubble

gum is

(A)inelastic
(B)elastic
(C)unit elastic
(D)perfectly inelastic

需求彈性我怎麼算都是1.8 結果我看答案居然是0.49

還是這題不能用弧彈性算呢?

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