Question 1103436
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Already answered.<br>
If this is a re-post, then please look at the statement of the problem as you show it.  It simply doesn't make sense.<br>
"Manny and Manuel can finish a certain job if manny works for 15 days and Manuel works for 3 days."<br>
fine... that is useful information.<br>
"if they both work for six days,..."<br>
that is not fine; there is something missing there; as it is, it gives us no useful information.<br>
"how long will it take each to do the job alone?"<br>
We can't tell unless you give us some useful information with the second statement.