David0822

61)mail contributes to 25% of all income, telephone contribute t percent, person contribute 225,000 less than all income. then tell you telephone=150,000, ask telephone contribute what percent of all income(注意题目给的是tele=150,000,很容易理解为mail=150,000)ans: 50%
【机委】:50%
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mail: 25%
tele: t%
person: X (total income) – 225000
mail + tele + person = X (total income)
(1) (25% + t% )X + (X – 225000) = X => (25% + t%) X = 225000
(2) t% X = 150000
t% = 50%