A contractor completed five-ninths of a job before a second contractor completed an additional one-third. What fraction of the job is left undone?  Choose the correct choice from the following options
A) one-ninth	B) two-thirds	C) four-ninths	D) eight-ninths	E) none
Ans is A   Fraction of Job completed = 5/9 + 1/3 = 5/9 + 3/9 = 8/9 Fraction left undone = 1 - 8/9 = 9/9 - 8/9 = 1/9 i.e. one-ninth
<result>A</result>
A contractor completed five-ninths of a job before a second contractor completed an additional one-third. What fraction of the job is left undone?