破解数学prep2-52请教！

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52.   4349-!-item-!-187;#058&003856

For Manufacturer M, the cost C of producing x units of its product per month is given by C = kx + t, where C is in dollars and k and t are constants.  Last month, if Manufacturer M produced 1,000 units of its product and sold all the units for k + 60 dollars each, what was Manufacturer M's gross profit on the 1,000 units?

 

(1)  Last month, Manufacturer M's revenue from the sale of the 1,000 units was $150,000.

 

(2)  Manufacturer M's cost of producing 500 units in a month is $45,000 less than its cost of producing 1,000 units in a month.

--------------------------------------------------------------------------------------------------------------------------------------------------------【答案】E

条件(1)中的revenue指什么呢？如何算？

谢谢~

biglin1987

cost成本  C = kx + t

revenue收入  （k + 60是一个产品的收入，即 单位收入，1000个的收入是（k+60）×1000） 

profit利润

首先明确  ：利润=收入-成本 ，profit=（k+60）×1000- （1000k + t）

条件（1）（k+60）×1000=150000 ，求不出t，不充分

（2）1000k + t-（500k+t）=45000，求不出t，不充分

两条件结合仍然无法得出t的值

故选e

不知道对不对^_^

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恩，谢谢ls~~破解说revenue=gross profit-expense，说得我糊涂极了