pp-1-ds-135

Kath1985

135.
During a one-day sale, astoresoldeachsweaterofacertain type for $30 more than the store's cost to purchase eachsweater. How many of these sweaters were sold during the sale?

(1) During the sale, the total revenue from the sale of these sweaters was $270.

(2) During the sale, the storesoldeachof these sweaters at a price that was 50 percent greater than the store's cost to purchase eachsweater.

Ans:C
我選A 因為
條件1   S=C+30
設賣出x件
(1) Sx-Cx=270 條件代入
(C+30)X-CX=270 30X=270 X=9件---SUFFICIENT
請問哪邊錯了呢?

gabriel1981

应该是把revenue和profit的概念搞混了，revenue=profit+cost