Question
‘A’ alone can complete a work in 15 days. ‘B’
alone can complete the same work in 20 days. If ‘A’ and ‘B’ work together for 5 days, then the remaining work can be completed by ‘A’ alone in how many days?Solution
Let the total amount of work = 60 units {LCM of 15 and 20} Then, efficiency of ‘A’ = 60/15 = 4 units/day Efficiency of ‘B’ = 60/20 = 3 units/day Combined efficiency of ‘A’ and ‘B’ = 4 + 3 = 7 units/day Work completed by ‘A’ and ‘B’ together in 5 days = 5 × 7 = 35 units Remaining work = 60 – 35 = 25 units Time taken by ‘A’ alone to complete the remaining work = 25/4 = 6.25 days
P can do a piece of work in 15 days, Q can complete double the work in 40 days and R can do the work in 20 days. If all of them together earn Rs. 3000, ...
- Alex and Ben can complete a job individually in 14 days and 21 days, respectively. If they take turns to work one day each, beginning with Alex, how long w...
‘X’ and ‘Y’ can do a task together in 15 days. If ‘X’ alone takes 25 days to complete it, then how much time will ‘Y’ take to finish the...
‘P’ and ‘Q’ can complete a task together in 24 days. If ‘P’ alone can do it in 40 days, find the number of days ‘Q’ alone will take to f...
A can complete a work in 40 days. B takes 20 days less than A to complete the same work. In how many days can both of them together complete 90% of the ...
P can do a piece of work in 30 days. Q do the same work in 40 days. R can do it in 35 days. P and R worked for 4 days and handed it to Q. Q worked for s...
X can do a piece of work in 15 days. He worked at it for 3 days and then Y finished it in 16 days. In how many days can X and Y together finish the work?
A job is done by 15 men in 30 days and 30 women in 20 days. How many days will it take for 8 men and 12 women to finish the work?
P can do a piece of work in 20 days, Q can do the same piece of work in 24 days while R can do it in 30 days. They started working together but after 4 ...
12 engineers complete designing 180 blueprints in 15 days. If the goal is to complete 270 blueprints in 18 days, how many engineers are required?
Relevant for Exams:
