<p>how do you do a problem such as the following:
Joe takes 5 hrs. to do a job and Jane takes 2 hrs. to do the same job. how long would it take if the two were working together?
is there like an equation or something?</p>
<p>Work to be done = x</p>
<p>Joe takes 5 hrs. to do x
and Jane takes 2 hrs. to do x</p>
<p>now they are working together --> </p>
<p>x+x=5+2
2x=7 </p>
<p>we don't want to know how long it takes when they do twice as much<br>
as they should do, so divide the equation by 2</p>
<p>x=3,5 </p>
<p>It takes 3,5 hrs. when they work together.</p>
<p>Remember: Kinda unorthodox approach to such a question.</p>
<p>I didn't get the same answer as Sorusch...I got approximately 1.43 hours, but I may have done it wrong. </p>
<p>In Algebra II I learned this: Suppose A equals the time it takes A to do a job, B equals the time it takes B to do a job, and T equals the time it takes them to do the same job working together. Then (1/A) + (1/B) = (1/T)</p>
<p>So,
(1/5) + (1/2) = (1/T)
(7/10) = (1/T)
7T = 10
T = 1.43</p>
<p>Uhhh Sorusch, the answer you provided doesn't make sense because it shouldn't take longer to finish the job when they work together than when one is working alone.</p>
<p>By your logic, if two people could finish the job in 5 hours, working together, it should take them 2x=5+5 2x=10 x=5 hours to finish the job, which doesn't make sense here.</p>
<p>yeah, yeahallie's answer is correct.</p>
<p>yeahallie's method is the way to do it boys and girls.</p>