Discussion :: Time and Work
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A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is :
Answer : Option D
Explanation :
A's 1 day's work =115;
B's 1 day's work =120;
(A + B)'s 1 day's work =[115+120]=760
(A + B)'s 4 day's work =[760∗4]=715
Therefore, Remaining work =[1-715]=815
I am prepare for job
Where from the 7/60 because I don't understand
How do they arrive to 7/60 in the first place
How do they substract 1-7/15
why cant we take work done by A in 4 DAYS as 4/15 and work done by B in 4 days as 4/20 and add A'S work and B'S work AND THEN SUBTRACT (4/15+4/20 = 2/5) LEFT OVER WORK =1-2/5=3/5