(好趕+) Stupid Maths Question!!!

2011-02-21 3:33 am

Q1) A seller has 10kg of tea A and 18kg of tea B. He mixes the teas in different ratios. For Class I tea, the ratio of A to B is 1:2 and that for class II is 2:1. If the profit for each kilogram of class I tea is $850 and that for class II tea is $800, how much of class I and class II should be produced in order to miximize the profit??ans:I-26, II-2 **If u are sure of your answer, give me the constraints only!!! No need to draw graph!!! Q2) In a match, the mean score of a team of m men and n women is 70.a) If the mean score of the men is 75 and the mean score of women is 62, find the ration m:n.

Show me the workings for Q2 ans: 8:5

回答 (1)

STEVIE-G™

2011-02-21 4:14 am

✔ 最佳答案

Question 1:
Let x and y be the weight of class I and II respectively and P be the profit

Objective:
maximize P=850x+800y

Subject to:
(1) x+y<=28
(2) (1/3)x+(2/3)y<=10 [Limited by the weight of tea A]
(3) (2/3)x+(1/3)y<=18 [Limited by the weight of tea B]
(4) x,y>=0

Question 2:
By using the fact that "the mean score of a team is 70":

(The sum of the score)/(total number)=70
(75m+62n)/(m+n)=70
(75(m/n)+62)/((m/n)+1)=70
75(m/n)+62=70((m/n)+1)
75(m/n)+62=70(m/n)+70
5(m/n)=8
m/n=8/5

Hence, the ratio m:n=8:5

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