posted by Brenda .
'A mason can build a wall in one-half the time it takes an apprentice. Together they build the wall in 12 hours. How long would it take the apprentice working alone to build the wall?' This needs to be worked using a table. The column headings are 'Time Alone', 'Rate', 'Time Together' and 'Work Accomplished'.
If this is algebra, you should not have to make tables.
Let the mason's rate be x walls per hour and the apprentice's rate be 0.5 x walls per hour. Working together, their rate is 1.5x walls per hour.
1.5x * 12 h = 1 wall
x = 1/18 wall per hour
x/2 = 1/36 wall per hour
The apprentice alone would need 36 hours