GWD23-4

[dianechiu]

All 48 seniors in a certain school take one of two English classes. What is te average (arithmetic mean) height of the seniors in the school?

(1)In the school, the average height of the seniors in the English class with the larger number of the students is 70 inches.

(2)In the school, the average height of the seniors in the English class with the smaller number of the students is (4/5) of the average height of the seniors in the other English class.

answer: E

一直想不透,麻煩大家幫我解惑,謝謝

[hey]

條件一:其只說較多人數那班的平均身高是70英吋, 並不知道另一班的身高
條件二:較少人數那班的平均身高比是另一班的平均身高的4/5, 但並不知道兩班的平均身高到底是多少
條件一加條件二:其根本不知道兩個班級的確切人數為多少, 所以根本求不出來
因此選選項(E)

[dianechiu]

原來是誤會題意了~
這樣我了解了~~ 謝謝