Question 851988
To solve, we need to set this word problem as an equation.


1.  If one man can dig a pit in 10 days, he can dig 1/10 of the pit per day.


2.  If another man can dig a pit in 20 days, he can dig 1/20 of the pit per day.


So, we can set up the equation as follows:


{{{1/10+1/20=1/x}}}


Now, we can solve for x, which will tell us how long it would take if the two men worked together.  To do this, first multiply each fraction by the LCD of all of the fractions, which is 20x.  This will give us:


2x + x = 20 ----->


3x = 20 ----->


x = 20/3 ----->


x ≈ 6.67 days