A can complete a task in 15 days, whereas B can do it in 20 days. If they work on it jointly for four days, the remaining proportion of the job is:
A. 1/4
B. 1/10
C. 7/15
D. 8/15
Answer:D
A can complete a task in 15 days, whereas B can do it in 20 days. If they work on it jointly for four days, the remaining proportion of the job is:
A. 1/4 B. 1/10 C. 7/15 D. 8/15
Explanation: 1/15 of A's 1 day's labour.1 day's labour for B = 1/20;1 day's work for (A + B) = ( 1/15+ 1/20 ) = 7/604 days of labour for (A + B) = ( 7/60 x 4/15 ) = 7.As a result, the remaining labour equals ( 1/15- 7/15 ) = 8.