Fourteen persons can do a work in 18 days. After 5 days of work, 6 workers left the work, and joined back on the last day of the work. In how many days the work got completed?

14 persons can do a work in 18 days
After 5 days 6 workers left.
These 5 workers joined on the last day of work.

Concept used:
If each person can do 1unit of work per day then n persons can do 1 × n unit work per day.

Calculation:
Let each person can do 1 unit of work per day

So,
⇒ 14 persons can do = 1 × 14 = 14 units/day
⇒ In 18 days, 14 persons can do = 18 × 14 = 252 units (Total work to be done)

Now,
In first 5 days, 14 persons completed
⇒ 14 × 1 × 5 = 70 units
In last day, 14 persons competed
⇒ 14 × 1 = 14 units

Then,
the total work completed in 6 days = 84 units

Now,
Work left =168 units
And persons left = 14 - 6 = 8 persons

So,
Time taken by 8 persons to complete to leftover work
⇒ 168/(8 × 1) = 21 days

So,
time taken to complete the whole work = 5 + 21 + 1 = 27 days

∴ The work got completed in 27 days.