A can do a work in 15 days and B in
20 days. If they work on it together for
4 days, then what is the fraction of the
work that is left?
(A) 1/4
(B)1/10
(C)7/15
(D)8/15
Answers
Answered by
2
D) 8/15
Take LCM of 15 and 20 as the total amount of work which is 60 units in this case.
A can do work in 15 days therefore amount of work done by A in 1 day is 60/15 = 4 units
B can do work in 15 days therefore amount of work done by A in 1 day is 60/20 = 3 units
Total amount of work done in 1 day =A work of 1 day+B's work of 1 day=4 units +3 units=7 units
Amount of work done in 4 days =4*7=28 units
Amount of Work Left = 60–28=32 units
Fraction of work left = Amount of work left/ Total Work = 32/60 = 8/15.
Answered by
1
Answer:
D
Step-by-step explanation:
A does 1/15 of work per day
B does 1/20 work per day
each day they do 7/60 work
after four days 28/60 or 7/15 work is done thus 8/15 work is left
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