Janet, an experienced shipping clerk, can fill a certain order in 3 hours. Tom, a new clerk, needs 4 hours to do the same job. How long does it take them working together?
1 Answer
Explanation:
If Janet can do the job in
Let's say that the total amount of time they take to do the job working together is
We can then write the equation
#1/3x + 1/4x = 1#
because
To solve this equation, rewrite the fractions so they have a common denominator, and find
#1/3x + 1/4x = 1#
#4/12x + 3/12x = 1#
#7/12x = 1#
#x=12/7 "hr"#
So, it takes them