A mason can build a wall in 9 hours less than an apprentice. Together they can build the wall in 6 hours. How long would it take the apprentice, working alone, to build the wall?

Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate. monthly temperatures: 63 degrees upper f comma 67 degrees upper f comma 71 degrees upper f comma 75 degrees upper f comma and 79 degrees upper fmonthly temperatures: 63° f, 67° f, 71° f, 75° f, and 79° f