GWD 02-Q10

[sugarcane]

on a certain date,Hannah ivested $5000 at x percent simple annual interest and a different amount at y percent simple annual interest .What amount did Hannah invest at y percent simple annaul interest?
(1) The total amount of interest earned by Hannah's due investment in one year was $900
(2) Hannah invested the $5000 at 6 percent simple annaul interest.

答案為E
我看不懂題目問什麼耶??

[FrankChang]

Hannah放5000元於年息x%的投資,另外放某個數目的錢在年息y%的投資,
問另外放在y%投資金額是多少!?
(1)900=5000*0.01x+?*0.01y,三未知數一條方程式
(2)x=6,與y%的投資無關
聯立(1)(2)兩未知數一條式子,所以選E了