A face questions, with a thick and a thin hose to the sink and pour the water, in order to make a sink full of water, rough water 40 minutes, 50 minutes thin pipes, water began only rough water for 10 minutes, after rough water and fine water pipes at the same time together, will end only with a fine water tank filled with water. A total injection time totaled 30 minutes.
1, the thickness of the pipe while water use is a few minutes? (14 minutes)
2, injected with the crude water quantity and proportion of the amount of injection with a fine tube is a few more than a few? (3 to 2)
The answer is out there already announced, as if to say somewhat vague. I talk about my first time to do this when it questions.
1. First locate This is a logical question, usually the first Optional title, this time you have to refer to the answer options
2. Try substituting the answer options, rapid problem-solving skills.
Solving: first assumed that the water tank is 100L, the crude water injection amount 100/40 = 2.5L / min, fine water 2L / min.
Start with a crude water injection only 10 minutes: water = water * 10 = 25L crude
Setting coarse and fine water pipes total injection time is x, only the last time a fine pipe 20-x.
（2.5+2）*x +2*（20-x）=75
Solve for x equal to 14, a total injection time of 14 minutes, and finally a single injection of fine water for 6 minutes.
Finally, I asked myself thinking about it, this unhappy life, come on! I wish you as soon as possible through the interview.