1. A can do a piece of work in 120 days and B can do the work in 150 days. They work together for 20 days. Then A leaves and B continues the work. 12 days after that, C joins the work and the work is completed in 48 more days. In how many days C can do it alone?
Answers
Answer:
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Answer:
I have tried the problem using LCM approach.
A→ 120
B→ 150
Total work = LCM (120,150) = 600
So,
A’s one day work will be 600/120 = 5
B’s one day work will be 600/150 = 4
Now, A+B work together for 20 days:
(A+B)’s total efficiency will be 5+4 = 9
Since they work together for 20 days, 9*20 = 180 which is the total work done.
Remaining work = 600–180 = 420.
B leaves, A alone continues the work for another 12 days:
A’s efficiency is 5 and he works for 12 days. So, 5*12 = 60 which is the work completed by A in 12 days.
Now, the remaining work will be 420 -60 = 360.
Then, A+C work for 48 days:
So, Total work / (efficiency of A+C) is 360/ 48 = 7.5 which is (A+C)’s one day work.
As we already know, A’s efficiency is 5,
C’s efficiency will be 7.5 - 5 = 2.5
Hence,
C alone complete the work in 600/ 2.5 = 240 days.
Hope this helps!
Cheers!