Mr Wong takes 3 days to paint a house. Mr Lim takes 5 days to paint the same house. If they both work together to paint the same house, how long will they take?
In 1 day, Mr Wong paints 1/3 of a house
In 1 day, Mr Lim paints 1/5 of a house
If they work together, they paint 1/3 + 1/5 = 8/15 of a house in 1 day
thus, to paint 1 house, they will need 15/8 = 1 7/8 days
8/15 in one day
less than 2 days