<p>Here is the question is:</p>
<p>If 500 pounds of mush will feed 20 pigs for a week, for how many days will 200 pounds of mush feed 14 pigs?
4</p>
<p>That was easy to solve, but the question is WHAT STRATEGY SHOULD BE USED IN SOLVING IT? OR HOW TO SOLVE IT?</p>
<p>If 1 worker can deliver 1 letter in 5 minutes, how many letters can 120 workers deliver in 2 hours?
24</p>
<p>Again the question is: HOW TO SOLVE IT? rather than what is the answer?</p>
<p>In order to solve this kind of questions, you have first to find out the relationships of the variables per unit.
Let’s take the example you’ve mentioned.
If 500 pounds of mush will feed 20 pigs for a week, for how many days will 200 pounds of mush feed 14 pigs?
500pounds / 20pigs = 25 pounds per pig per week
25 / 7= 25/7 pounds per pig per day
So you have found relationships, now you have to redo it inversely.
25/7 pounds per pig per day * 14 pigs = 50 pounds per day
200 /50 = 4 days</p>
<p>Now look at our solving procedures. First we look at the question and find 3 variables : mush , pig and time. Second we determine the variable that should be decline to 1 unit. Obviously, 1 pig and 1 day are easy to deal with as they have smaller numbers. Then we devide them respectively, and thus find the value of the main variable (mush) in terms of 1 unit of all other variables. Finally, we rebuild the model of the relations and find the answer.
The key to this kind of problems is to find the relationships between variables. Through the method above, you can solve it easily.
If you have any further questions, PM me or send emails to me.</p>
<p>There is another way that often works, especially when the problem has “nice” numbers.</p>
<p>You can do a sort of step by step adjustment, one variable at a time until you get numbers that match what they ask for…here’s what I mean:</p>
<p>1 worker does 1 letter in 5 minutes – now double that to get…
1 worker does 2 letters in 10 minutes – now times 6 to get…
1 worker does 12 letters in 60 minutes which is also 1 hour – double again to get…
1 worker does 24 letters in 2 hours – and finally, times 120 to get…
120 worders deliver 2880 letters in 2 hours.</p>
<p>This may seem longer, but the steps are easy and you don’t get tripped up by the units change that is often embedded in this kind of question. I know it would be harder with uglier numbers, but these kinds of problems don’t usually have ugly numbers…</p>
<p>^That was helpful. Thanks a lot. I guess you know how it feels to get a full Real SAT exam correct and when you are on the verge of getting an 800, you get messed up for such a disgusting sum!!! Thanks again!</p>