If all three work together, how long will they take to do the same work. Explain me clearly?
2006-12-20 00:13:01 · 8 answers · asked by raj_paragon 1 in Science & Mathematics ➔ Mathematics
In 30 days A will do the job once, B twice and C three times. So in 30 days, they do the work 6 times in total, so to do it once would take 5 days.
2006-12-20 00:16:08 · answer #1 · answered by Tom :: Athier than Thou 6 · 0⤊ 0⤋
If the amount of the work is x, A can do x/30 of the work per day (A works at the same rate, the work is divided equally to each day), and finishes it by doing for (30 days) a (x/30 of the work) = x work. Similarly, B can do x/15 of the work and C x/10 of the work. The work x has the same value for A,B,C. If they work together for a day, the work done on that day is x/30+x/15+x/10=x/30+2x/30_3x/30=6x/30=x/5. In 5 days you get the 5 x/5=x work.
2006-12-20 00:22:31 · answer #2 · answered by supersonic332003 7 · 0⤊ 0⤋
In x days, A does x/30 of the job, B does x/15 of a job, C does x/10 of a job, and when added they do the whole job equalling 1.
(x/30) + (x/15) + (x/10) = 1
(x/30) + (2x/30) + (3x/30) = 30/30
6x = 30
x=5
2006-12-20 00:25:11 · answer #3 · answered by fcas80 7 · 0⤊ 0⤋
A's 1 day's work=1/30
B's 1 day's work=1/15
C's 1 day's work=1/10
their combined work in 1 day=1/30+1/15+1/10
since 30 is thwe LCD
=1/30+2/30+3/30
=6/30
=1/5
so they will finish the work in reciprocal of (1/5) days
that is they will finish in 5 days working together
2006-12-20 06:06:24 · answer #4 · answered by raj 7 · 0⤊ 0⤋
Another way is to say that A does 1/30th of the work per day. B does 1/15th of the work per day, and C does 1/10th of the work per day. So the equation works like this.
1 Full Job = N/30 + N/15 + N/10 (N = Number of Days)
1 = N/30 + 2N/30 + 3N/30
1= N + 2N + 3N / 30
30 = N + 2N + 3N
30 = 6N
5=N
5 Days to complete Job
2006-12-20 00:21:23 · answer #5 · answered by bourne3141592654 2 · 0⤊ 0⤋
A can do 1/30th part of work in 1 day
B can so 1/15 part of the work in 1 day and C can do 1/10th part of work in 1 day.
A,B and C can together do (1/30+1/15+1/10)th part of work
i.e. 1/5th part of work.
If in 1 day A,B and C can do 1/5th part of work then they will complete the work in 5 days
ans=5 days
2006-12-20 01:32:53 · answer #6 · answered by Twarita 2 · 0⤊ 0⤋
let us say it takes x days for all tree together.
1/30+1/15+1/10=1/x
6/30=1/x
x=5 days
2006-12-20 00:34:18 · answer #7 · answered by iyiogrenci 6 · 0⤊ 0⤋
i thinh its 5 days
2006-12-20 00:23:00 · answer #8 · answered by Anonymous · 0⤊ 0⤋