Question

A and b complete a work in 8 days. b alone complete that work in 12 days. b alone worked for 4 days. after that how long will a alone take to complete the work.

Answer 1

Let the no. of days in which A can complete the work be x
Then the work done by A in 1day will be 1/x
Now the work done by B in 1day will be 1/12
Now the work done by them in 1day will be 1/8
Now,(1/x)+(1/12)=1/8
(12+x)/12x=1/8
12+x=3x/2
x=24 days
Part of the work done by B in 4 days=4×(1/12)
=3/4
Left portion of the work =1-(3/4)
=1/4
Let the time taken by A to complete this 1/4 work be y days
Then, y×1/24=1/4
y=6 days
Hence A will take 6 days to complete the work left work.
HOPE THIS HELPS !!!!!