X and Y can paint the house in 18 days, Y and Z in 24 days and X and Z in 36 days. In how many days Y will finish it separately?

Asked by Topperlearning User | 4th Jun, 2014, 01:23: PM

Expert Answer:

X and Y can paint the house in 18 days (X + Y)'s 1 day's work =

Y and Z can paint the house in 24 days (Y + Z)'s 1 day's work =

X and Z can paint the house in 36 days (X + Z)'s 1 day's work =

Adding, we get

2(X + Y + Z)'s 1 day's work =

Thus, (X + Y + Z)'s 1 day's work =

Y's 1 day's work = [(X + Y + Z)'s 1 day's work] - [(X + Z)'s 1 day's work]

Hence, Y alone can paint the house in days.

Answered by  | 4th Jun, 2014, 03:23: PM