let

x = the number of days Andrew needs to paint the house alone

1/x houses per day is the rate of Bailey

3x = the number of days Bailey needs to paint the house alone

1/(3x) houses per day is the rate of Andrew

The year they painted it together it took them 5 days:

1/x + 1/(3x) = 1/5

by solving the equation we find:

x = 20/3 days

x = 6 2/3 days

x = 6 days 2*24/3 hours

x = 6 days 16 hours

click here to see the step by step solution of the equation:

3x = 3*(20/3) = 20 days

Bailey needs 20 days to paint the house alone.

Andrew needs 6 days and 16 hours to paint the house alone.