Question 53329: a,b and c can finish a job in 6 days. if b and c work together , the job will take 9 days, if a and c work together the job will take 8 days in how many days can each man working alone do the job? please show formula
Answer by venugopalramana(3286)   (Show Source):
You can put this solution on YOUR website! OK YOU ARE NOT ABLE TO SOLVE ..SEE BELOW...
a,b and c can finish a job in 6 days
if b and c work together , the job will take 9 days, if a and c work together the job will take 8 days in how many days can each man working alone do the job? please show formula
A+B+C..CAN DO IN 6 DAYS ....1 JOB
A+B+C..CAN DO IN 1 DAY......1/6 JOB........................I
B+C..............9...........1 JOB
B+C..............1...........1/9 JOB.........................II
A+C..............8............1 JOB
A+C..............1............1/8 JOB ........................III
HENCE EQN.I - EQN.II GIVES
A+B+C-B-C=A......1..........1/6 - 1/9 = 1/18 JOB............IV
A CAN DO IN......1/(1/18)=18DAYS.......1 JOB......ANSWER FOR A
EQN.I-EQN.III GIVES SIMILARLY
A+B+C-A-C=B......1...........1/6 - 1/8 = 1/24...............V
B CAN DO IN .....1/(1/24)=24 DAYS......1 JOB.........ANSWER FOR B
EQN.III - EQN.IV...GIVES
A+C-A=C...........1.........1/8 - 1/18 = 5/72
C CAN DO IN ......1/(5/72)=72/5=14.4 DAYS ...1 JOB....ANSWER FOR C
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A worker can cover a
parking lot with asphalt in ten hours. With the help
of an assistant, they can do the job in six hours. How
long would it take the assistant, working alone, to
cover the parking lot with asphalt?
1 solutions
Answer 13786 by venugopalramana(1619) About Me on
2006-01-27 00:28:05 (Show Source):
A worker can cover a parking lot with asphalt in ten
hours.
HENCE IN 1 HOUR HE CAN DO 1/10 JOB.
With the help of an assistant, they can do the job in
six hours.
HENCE IN ONE HOUR BOTH (HE+ASSISTANT)CAN DO 1/6 JOB
How long would it take the assistant, working alone,
to cover the parking lot with asphalt
HENCE IN 1 HOUR ASSISTANT ALONE CAN DO 1/6 - 1/10 JOB
=(5-3)/30=2/30=1/15 JOB
HENCE ASSISTANT ALONE CAN DO 1 JOB IN 1/(1/15) HOURS =
15 HOURS.
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Answer 16715 by venugopalramana(1167) About Me on
2006-03-12 11:04:12 (Show Source):
need help plz...heres the question "There are three
friends named Allan, Bobby and Charlie. The three
friends want to know their individual rate in
finishing a job. Allan and Bobby can finish the job in
42 days, Bobby and Charlie can finish the job in 31
days, and Allan and Charlie can finish the job in 20
days. Solve the rate of each individual."
LET ALLAN TAKE A DAYS TO DO THE JOB ALONE
HENCE ALLAN ALONE CAN DO IN 1 DAY 1/A JOB
LET BOBBY TAKE B DAYS TO DO THE JOB ALONE
HENCE BOBBY ALONE CAN DO IN 1 DAY 1/B JOB
LET CHARLIE TAKE C DAYS TO DO THE JOB ALONE
HENCE CHARLIE ALONE CAN DO IN 1 DAY 1/C JOB
FROM ABOVE WE GET ...
ALLAN AND BOBBY CAN DO IN 1 DAY ..1/A +1/B =(A+B)/AB
JOB..
SO DAYS THEY TAKE TO COMPLETE THE JOB
=AB/(A+B)=42..OR..1/A+1/B=1/42..........I BOBBY AND
CHARLIE CAN DO IN 1 DAY ..1/B +1/C =(B+C)/BC JOB..
SO DAYS THEY TAKE TO COMPLETE THE JOB
=BC/(B+C)=31..OR..1/B+1/C=1/31.........II
ALLAN AND CHARLIE CAN DO IN 1 DAY ..1/A +1/C =(A+C)/AC
JOB..
SO DAYS THEY TAKE TO COMPLETE THE JOB
=AC/(A+C)=20..OR..1/A+1/C=1/20........III
EQNI+EQNII+EQNIII GIVES...
2{(1/A)+(1/B)+(1/C)}=(1/42)+(1/31)+(1/20)
(1/A)+(1/B)+(1/C)=(1/2)*{(1/42)+(1/31)+(1/20)}.........IV
EQN.IV-EQN.I GIVES
1/C=
(1/2)*{(1/42)+(1/31)+(1/20)}-1/42....OR.....C=34.2
DAYS
EQN.IV-EQN.II GIVES.......
1/A=(1/2)*{(1/42)+(1/31)+(1/20)}-
1/31...OR......A=48.1 DAYS
EQN.IV-EQN.III GIVES....
1/B=(1/2)*{(1/42)+(1/31)+(1/20)}-
1/20....OR.....B=329.6 DAYS--------------------------------------------------------
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