Question
P and Q need 8 days to complete a work. Q and R need 12 days to complete the same work. But P, Q and R together can finish it in 6 days. How many days will be needed if P and R together do it?
Answer: Option B
LET WORK DONE BY P IN 1 DAY = P
WORK DONE BY Q IN 1 DAY =Q
WORK DONE BY R IN 1 DAY = R
P + Q = 1/8 —(1)
Q + R= 1/12 —(2)
P+ Q+ R = 1/6 —(3)
(3) – (2) => P = 1/6 – 1/12 = 1/12
(3) – (1) => R = 1/6 – 1/8 = 1/24
P + R = 1/12 + 1/24 = 3/24 = 1/8
=> P AND R WILL FINISH THE WORK IN 8 DAYS
Was this answer helpful ?
LET WORK DONE BY P IN 1 DAY = P
WORK DONE BY Q IN 1 DAY =Q
WORK DONE BY R IN 1 DAY = R
P + Q = 1/8 —(1)
Q + R= 1/12 —(2)
P+ Q+ R = 1/6 —(3)
(3) – (2) => P = 1/6 – 1/12 = 1/12
(3) – (1) => R = 1/6 – 1/8 = 1/24
P + R = 1/12 + 1/24 = 3/24 = 1/8
=> P AND R WILL FINISH THE WORK IN 8 DAYS
Was this answer helpful ?
More Questions on This Topic :
Latest Videos
Latest Test Papers
Submit Solution