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AIME 2007 II · 第 4 题

AIME 2007 II — Problem 4

专题
Contest Math
难度
L4
来源
AIME

题目详情

Problem

The workers in a factory produce widgets and whoosits. For each product, production time is constant and identical for all workers, but not necessarily equal for the two products. In one hour, 100100 workers can produce 300300 widgets and 200200 whoosits. In two hours, 6060 workers can produce 240240 widgets and 300300 whoosits. In three hours, 5050 workers can produce 150150 widgets and mm whoosits. Find mm.

解析

Solutions

Suppose that it takes xx hours for one worker to create one widget, and yy hours for one worker to create one whoosit.

Therefore, we can write that (note that two hours is similar to having twice the number of workers, and so on):

100=300x+200y100 = 300x + 200y 2(60)=240x+300y2(60) = 240x + 300y 3(50)=150x+my3(50) = 150x + my

Solve the system of equations with the first two equations to find that (x,y)=(17,27)(x,y) = \left(\frac{1}{7}, \frac{2}{7}\right). Substitute this into the third equation to find that 1050=150+2m1050 = 150 + 2m, so m=450m = \boxed{450}.

Video Solution by OmegaLearn

https://youtu.be/00Ngozqw2d0?t=542

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