Aarif, Arun and Abraham can do a work in 12, 20 and 24 days, respectively. They all begin together. Aarif leaves the work 1 day, Arun 3 days and Abraham 4 days before its completion. In how many days is the work finished?

8

Aarif = 12 days, Arun = 20 days, Abhraham = 24 days,

Here, (x -1) x 10 + (x - 3) x 6 + (x - 4) x 5 = 120

⇒ 10x -10 + 6x - 18 + 5x - 20 = 120

⇒ 21x - 48 = 120

⇒ 21x = 168

⇒ x = 8 

Therefore, the work work will be finished in 8 days.