Last week, your delivery runs took 7 hours 12 minutes on Monday, 6 hours 46 minutes on Wednesday, and 6 hours 53 minutes on Friday? What was your average time for a delivery run?

Answer:[tex]\boxed{\textbf{6:57}}[/tex]Step-by-step explanation:[tex]\text{Average time} = \dfrac{\text{total time}}{\text{number of runs}}[/tex] 1. Add the hours and minutes separately [tex]\begin{array}{rcr}7 &: & 12\\6 & : & 46\\6 & : & 53\\\mathbf{19} &:& \mathbf{111}\\\end{array}[/tex] 2. Calculate the average time [tex]\text{Average time} = \dfrac{19:111}{\text{3}}[/tex]The hours do not divide evenly by 3. (a) Convert the hours to a multiple of 3. Subtract 1 h  from the hours and add 60 min to the minutes [tex]\begin{array}{rcr}19 & : & 111\\- 1 & : & + 60\\\mathbf{18} & : & \mathbf{171}\\\end{array}[/tex]Now, the hours are divisible by 3. (b) Divide by three Divide the hours and the minutes separately[tex]\text{Average time} = \dfrac{18:171}{\text{3}} = \mathbf{6:57}\\\\\text{The average time for a delivery run was $\boxed{\textbf{6:57}}$}[/tex]