Question 984684
The equation for how long your are running each day is given by
{{{12 + (w-1)6}}}
That says in the first week, you will run 12+(1-1)6 = 12
The second week you will run 12+ (2-1)*6 = 18 minutes etc

You are asked, how many weeks before you are running for 60 minutes?

{{[RunningTime = 12 + (weeknumber -1)*6}}}
{{{60 = 12 + (weekNumber -1)*6}}}
{{{48 =  (weekNumber -1)*6}}}
{{{48/6 = (weekNumber -1)}}}
{{{8 = weekNumber -1}}}
{{{9 = weekNumber}}}
So by the 9th week, you are running for 60 minutes.
Go easy on that knee!