Question

A and B can do a piece of work in 12 days, B and C can do it in 15 days while C and A can finish it in 20 days. If A, B and C works together, in how many days will they finish the work? In how many days will each one of them finish it, working alone?
my main question is that how 1/2 came during finding a+b+c 1day work
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Answer 1

Answer:

10 Days

Step-by-step explanation:

Now that you are asking that how did half come.

A and B one day work = 1/12

B and C one day work = 1/15

C and A one day work = 1/20

Now if we observe closely then each of them is working for 2 days.

A is first working with B and then C.

B is first working with A and then C.

C is first working with B and then A .

So when we get 1/5 after adding them we actually have counted their two days but the question asks for their one day's work. So we have to multiply them with 1/2 or divide them by 2 to get the actual answer.

I hope your confusion is clear. Please mark me as brainliest if you found this helpful.