Question

3. A can do a work in 15 days and B in 20 days.
if they work together on it for 4 days, what
fraction of the work will be left?​

Answer 1

Answer:

The 3 was remaining 30 is the right answer

Answer 2

Answer:

Amount of work A can do in 1 day=

1 /15

Amount of work B can do in 1 day =

1/ 20

Amount of work done by A and B in 1 day=

1/ 15 + 1/20 = 7/60

Amount of work A and B can together do in 4 days =4× 7/60 = 7/15

Fraction of work left = 1 - 7/15 = 8/15