A and B can complete a certain work by themselves in 10 days and 12 days respectively, while C takes 20 days for the same job. A and B start working on the job together but leave after 3 days. C then completes the remaining job alone. For how long did C work?
Answers
Answer:
Given A can do the work in 10 days ,B can do the work in 12 days and C can do the work in 15 days.
Then A's one day's work =
10
1
B's one day's work =
12
1
C's one day's work =
15
1
Then (A+B +C)'s one day's work =
10
1
+
12
1
+
15
1
=
1800
450
=
4
1
(A+B+C)'s two days' work =
4
1
×2=
2
1
But B leaves 3 days before the work gets finished, so C does the remaining work alone
C's 3 days' work =
15
1
×3=
5
1
Then work done in 2+3 days =
2
1
+
5
1
=
10
7
Work done by B+C together =1−
10
7
=
10
3
(B + C)'s one day work =
12
1
+
15
1
=
20
3
So number of days worked by B and C together=
10
3
×
3
20
=2 days
Then total work done =2+3+2=7 days
Given A can do the work in 10 days ,B can do the work in 12 days and C can do the work in 15 days.
Then A's one day's work =
10
1
B's one day's work =
12
1
C's one day's work =
15
1
Then (A+B +C)'s one day's work =
10
1
+
12
1
+
15
1
=
1800
450
=
4
1
(A+B+C)'s two days' work =
4
1
×2=
2
1
But B leaves 3 days before the work gets finished, so C does the remaining work alone
C's 3 days' work =
15
1
×3=
5
1
Then work done in 2+3 days =
2
1
+
5
1
=
10
7
Work done by B+C together =1−
10
7
=
10
3
(B + C)'s one day work =
12
1
+
15
1
=
20
3
So number of days worked by B and C together=
10
3
×
3
20
=2 days
Then total work done =2+3+2=7 days
please give brainliest