
Jordan K. answered 09/01/15
Tutor
4.9
(79)
Nationally Certified Math Teacher (grades 6 through 12)
Hi Sarah,
The key to solving work problems is to find out what part of a whole job each person contributes when doing the job together.
Julio's portion of the completed job can be expressed by this ratio:
5.83 / x (hrs. worked together / hrs. worked alone)
Julio's portion of the completed job can be expressed by this ratio:
5.83 / 10 (hrs. worked together / hrs. worked alone)
5.83 / 10 (hrs. worked together / hrs. worked alone)
Adding these portions together to equal 1 whole completed job gives us our equation, which we can then use to solve for our unknown (x):
(5.83 / x) + (5.83 / 10) = 1
(10x)(5.83 / x) + 10x(5.83 / 10) = (10x)(1)
58.3 + 5.83x = 10x
10x - 5.83x = 58.3
4.17x = 58.3
x = 58.3 / 4.17
x = 13.98 (Julio's hours to complete
the job alone)
In work problems, the principle to always remember is that the sum of the individual work portions is equal to one completed task.
Thanks for submitting this problem and glad to help.
God bless, Jordan.
Sarah C.
09/01/15