A does a work in 15 days B and C does the same work in 12 and 20 days respectively

Let they complete work in "x" days
C works for 2 days= 2/20
B works for (x-3) days=(x-3)/12
A works for x days= x/15
=>2/10+(x-3)/12+x/15=1
=>x=7.66
11 years agoHelpfull: Yes(10) No(0)
let total work=60 unit
then everyday,
A do=4 unit
B do=5
c do=3 unit
1st 2 days a+b+c do =[4+5+3]*2=24unit
remaining=36 unit
last 3 days A does=4*3=12unit
remaining =36-12=24unit
now (a+b) does this work together..(a+b) does(4+5)=9 unit everyday
so time required=(24/9)=2.66days
so total days req.=(2+3+2.66)=7.66days
11 years agoHelpfull: Yes(4) No(0)
1=2(1/15+1/12+1/20)+x(1/12+1/15)+3*1/15,where x is number of days A and B worked together.
from here x=2.66
so total number of days=2+2.66+3=7.66
11 years agoHelpfull: Yes(3) No(0)
let work completed in x days
so,(2/20)+(x-3)/12+(x/15)=1
(18+15x-45+12x)/180=1
27x-27=180
x=180/27=6.66666= 7 approx
11 years agoHelpfull: Yes(1) No(1)
7*7=49
1*1=1
49+1=50
7*1=7
ans 7
11 years agoHelpfull: Yes(0) No(2)
9.75 days
11 years agoHelpfull: Yes(0) No(2)

A does a work in 15 days B and C does the same work in 12 and 20 days respectively. C left the work after two days and B left before complimantation of 3 days. Find the total no. of days in which work completed.