in 2 h, kelly laid new floor tile over 1/5 of the room. when she was joined by annette, the rest of the work was completed in 3h. how long would it have taken annette to do the entire job alone

Annette will take 6 hours to do the entire job alone.

Step-by-step explanation:

Given: Time taken by Kelly to do of job = 2 hours

i.e. Time for complete job done alone by Kelly =

Rest of work = of the job

 of the complete job done by both Kelly and Annette in 3 hours

Time would be taken by then to do entire job together =

Let t be the time taken by Annette to do job alone.

Then, as per situation

hence, Annette will take 6 hours to do the entire job alone.