GWD 04-04

[jerry7271]

For a recent play performance, the ticket prices were $25 per adult and $15 per child. A total of 500 tickets were sold for the performance. How many of the tickets sold were for adults?

(1) Revenue from ticket sales for this performance totaled
$10,500.
(2) The average (arithmetic mean) price per ticket sold was $21.

答案是D，我卻選E...兩個差異性很大的答案，差點暈倒！！
誰能教教我啊...

[yoyu.tw]

For a recent play performance, the ticket prices were $25 per adult and $15 per child. A total of 500 tickets were sold for the performance. How many of the tickets sold were for adults?

(1) Revenue from ticket sales for this performance totaled
$10,500.
(2) The average (arithmetic mean) price per ticket sold was $21.

答案是D，我卻選E...兩個差異性很大的答案，差點暈倒！！
誰能教教我啊...

簡短回覆 題目給的條件 25x+15y=??? 還有x+y=15
條件一： 25x+15y=10500 充分
條件二：25x+15y=500*21 就這樣.........想一想就通了

加油 我下禮拜考 繼續去唸書^^ 衝阿

[jerry7271]

For a recent play performance, the ticket prices were $25 per adult and $15 per child. A total of 500 tickets were sold for the performance. How many of the tickets sold were for adults?

(1) Revenue from ticket sales for this performance totaled
$10,500.
(2) The average (arithmetic mean) price per ticket sold was $21.

答案是D，我卻選E...兩個差異性很大的答案，差點暈倒！！
誰能教教我啊...

簡短回覆 題目給的條件 25x+15y=??? 還有x+y=15
條件一： 25x+15y=10500 充分
條件二：25x+15y=500*21 就這樣.........想一想就通了

加油 我下禮拜考 繼續去唸書^^ 衝阿

感謝啊...我腦袋生鏽了...