Question 1009210
Let x=amount of time it takes Bob to clean the house
Then Bob works at the rate of 1/x house per hour
John cleans the house in x-1 hours
So John cleans at the rate of 1/(x-1) house per hour
Together they clean at the rate of 1/3 house per hour
sooo
1/x +1/(x-1)= 1/3  multiply each term by 3x(x-1)
3(x-1)+3x=x(x-1) 
3x-3+3x=x^2-x 
x^2-7x+3=0 
solve using quadratic formula and we get 
x=~6.54 hrs and
x=~0.46 hrs---this cannot be correct.  Can't have John cleaning in negative hours.
So the answer is x~=6.54 hours---time it takes Bob
Then 5.54 hours----time it takes John
CK
1/6.54 + 1/5.54 =1/3
0.1529 + 0.1805=0.3333
0.3334~~~~~0.3333

Hope this helps--ptaylor