## A can do a peice of work in 15 days and B in 20 days .If they together work on it for 4 days .then the fractions of work is left​

Question

A can do a peice of work in 15 days and B in 20 days .If they together work on it for 4 days .then the fractions of work is left​

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2 months 2021-11-10T19:49:12+00:00 2 Answers 0 views 0

## Answers ( )

A can do a work in 15 days and B in 20 days

A can do the work in 15 days.

Thus A finishes in one day = 1/15 work.

B finishes in one day = 1/20 work

Together, they finishes in one day

1/15 + 1/20 =7/60 work

If they work together for 4 days then what is the fraction of work that is left?

In 4 days they will finish work = 4 × 7/60 = 7/15 work

Remaining work left = 1 – 7/15

= (15 – 7)/15

= 8/15

The fraction of work left is 8/15

Answer : The fraction of work left is 8/15

2. Step-by-step explanation:

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.