[問題]天山3 30

[balanana]

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.

Ans:D

我選C,可否問為什麼是D??
謝謝~

[annitatu]

A是adult購買的張數,c是小孩買的張數
題目已知：A+C=500
(1)25A+15C=10,500=>充份
(2)25A+15C=21*500=>充份
所以是D嘍…
應該沒錯吧~~ccc

[balanana]

謝謝~原來我漏了A+C=500
感激:)