Simplify the fraction 4t2-16/8/t-2/6

The first thing we are going to do in this case is to rewrite the expression:
 4 (t2-4) / 8 / t-2/6
 4 (t-2) (t + 2) / 8 / t-2/6
 We now use the double C:
 24 (t-2) (t + 2) / 8 * (t-2)
 We simplify similar terms:
 24 (t + 2) / 8
 3 (t + 2)
 
 The simplified expression is:
 3 (t + 2)

The answer would be 13.5 minutes.