Question

A can do a piece of work in 10 days and B in 20 days. They begin together but A leaves 2 days before the completion of the work. In how many days will the whole work be completed?​

Answer 1

*Question:—

A can do a piece of work in 10 days and B in 20 days. They begin together but A leaves 2 days before the completion of the work. In how many days will the whole work be done?

*Answer:—

A can do the work in 10 days

B can do the work in 20 days

Therefore,

Their efficiencies

Total work = LCM(10,20)= 20 units

A's efficiency= 20/10= 2 units of work/day

B's efficiency= 20/20= 1 unit of work / day

So, according to the question

It takes n days to complete the total job and A leaves 2 days early. So A works for n-2 days and B works for n days

So,

A's work in n-2 days + B's work in n days = 20 units.

Or,

2(n-2) + 1(n)= 20

Or,

n = 8 days

So,

The work gets completed in 8 days.