Question

It takes pipe A 20 days to fill a fish pone. Pipe B takes 15 days find how long it takes both pipes together to fill the pond.? How do you set up the problem, that's what i need help with.

Answer 1

................sigh.
A needs 20 days
B needs 15 days
per day A can do 1/20 job.
per day B can do 1/15 of job.
days(1/20) + days(1/15) = 1

Answer 2

1/20+1/15
3/60+4/60 = 7/60

Answer 3

a=20a=v
b=15b=v
da+db=v

Answer 4

royal..7/60 is the part of pone fill by both A & B in a day.
so the totl no of days taken = 60/7=8 days 13 hrs.

Answer 5

Yes, you are right. I missed that part.

Answer 6

thanx royal