Question

A and B can do a piece of work in 72 days. B and C can do it in 120 days. A and C can do it in 90 days. In what
time can A alone do it?

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Answer 1

Answer:

120 Days

Step-by-step explanation:

Given that,

A+B=72 days, B+C=120 days, A+C=90 days.

So now calculate the Total Work by taking the L.C.M which is equal to 360.

Therefore, Total work = 360 unit…. (i)

Now we will get the one day work

A+B=5 unit work(360/72)…. (ii)

B+C=3 unit(360/120)…. (iii)

A+C=4 unit(360/90)…. (iv).

By adding these we get,

2(A+B+C)=12 unit

A+B+C=6 unit…. (v)

Now from (iii) and (v) we'll get the A's one day work, which is equal to 3 unit

A=3 unit…. (vi)

Now from (i) and (vi) we'll get the days that A can complete the work alone.

i.e, 360/3= 120 days.. Ans