Question 764118
anil can do work in 10 days and babbu in 8 days.
 anil and babbu can do the work on alternate days 
if anil begins the work, then the work can be finished
 in how many days
:
Let d = no. of days worked by Anil
and
(d-1) = no. of days worked by Bab
:
Let the completed job = 1
{{{d/10}}} + {{{((d-1))/8}}} = 1
Multiply by 40 to clear the denominators, results:
4d + 5(d-1) = 40
4d + 5d - 5 = 40
9d = 40 + 5
9d = 45
d = {{{45/9}}}
d = 5 days worked by Anil
and
4 days worked by Bab 
so
It will take 9 days to complete the job
:
see if that checks out
{{{1/10}}}+{{{1/8}}}+{{{1/10}}}+{{{1/8}}}+{{{1/10}}}+{{{1/8}}}+{{{1/10}}}+{{{1/8}}}+{{{1/10}}} = {{{5/10}}} + {{{4/8}}} = 1