A can complete a project in 20 days and B can complete the same project in 30 days. If A and B start working on the project together and A quits 10 days before the project is completed, in how many days will the project be completed?
A. 18 days
B. 27 days
C. 26.67 days
D. 16 days
E. 12 days
_________________
together they would take :
1/20+1/30 = 1/12 and that's equivalent to 12 days to do the job
this means that A quited after completing the second day...
so: A did 2/20 =1/10 of the job
B did 2/30 =1/15 of the job on the second day
together they did (1/10)+(1/15) = 1/6 of the job
if B takes 30 days to do 1 job; how much time would he take to do 1-(1/6) of the job?
R: 5/6 * 30= 25 days
so the full time = 25 days of B's work plus 2 days of (B+A)'s work = 27 days
the answer is B
A. 18 days
B. 27 days
C. 26.67 days
D. 16 days
E. 12 days
_________________
together they would take :
1/20+1/30 = 1/12 and that's equivalent to 12 days to do the job
this means that A quited after completing the second day...
so: A did 2/20 =1/10 of the job
B did 2/30 =1/15 of the job on the second day
together they did (1/10)+(1/15) = 1/6 of the job
if B takes 30 days to do 1 job; how much time would he take to do 1-(1/6) of the job?
R: 5/6 * 30= 25 days
so the full time = 25 days of B's work plus 2 days of (B+A)'s work = 27 days
the answer is B
