Sunday, September 28, 2008

Work Problem 1 Solution

In this Algebra work word problem solution the way to figure out the answer is to realize that they work a fractional part of work each hour. So in 1 hours time Steve does 1/9 of his work, so in 9 hours he does 9/9 or his whole job. Same thing goes for Joe except he gets 1/10th of his job done in an hour. For just one guy, take Steve for instance, the algebra for his work by himself would be (1/9)x = 1 or x/9 = 1 which makes x = 9 or 9 hours. for Joe it would be x/10 = 1 or 10 hours. Together they would take x/9 + x/10 = 1 hours(x) to get the job done.

x/9 + x/10 = 1
multiply by 90
10x + 9x + 90
19x = 90
x = 90/19

90/19 = 4.74 or approximately 4 hours and 45 minutes (.75 would 3/4ths of an hour or 45 minutes). If you want it exact just take the fractional part(.7368) and multiply by 60. You'll end up with 44.2 which is 44 minutes and .2*60 seconds or 12 seconds. The detailed answer would be 4 hours 44 minutes and 12 seconds. So if he hires both of these guys he'll get the lawn mowed before 6 hours.


  1. I'm studying for the asvab.. and in my book my study guide, shows a "formula" to solve problems like this for example AxB over A+B = anwser.

    And in this case would be 9x10 = 90 over 9+10 = 19

    so, 90/19= 4.73

    Well, that is to me the simplest way to do this kind of problem but I struggle when there is more than two people or when it saids something like "if the first preson start late... then.." they expect you to find the anwser for the two people when one of them got late to work and the another one has already work his/her part and then with the late person they have to get it done in certain time and that's when I don't know how to apply the formula AxB/A+B.

    could you help me?

  2. I need help too although thanks for the formula AxB over A+B. It really helps.


  3. check out some of the other problems like this on here-- and/or submit a question about the topic.

  4. why did you used 90 to multiply it to your algebraic equation?


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