Question 248629
Faster maid's rate of working + slower maids rate = rate working together
Let {{{x}}} = slower maids rate of working in (1 house cleaned)/(time to clean it)
then, Faster maid's rate = {{{3x}}}
{{{x + 3x = 1/3}}} (note: 1/3 is: (1 house/(3 hours))
{{{3x + 9x = 1}}}
{{{12x = 1}}}
{{{x = 1/12}}}
The slower maid can clean 1 house in 12 hours
The faster maid's rate is:
{{{3x = 3*(1/12) = 3/12}}}
{{{3/12 = 1/4}}}
The faster maid can clean the house in 4 hours