Gavin is starting a running plan to train for a race. In the first week of his running plan, Gavin will run 5 miles. The plan calls for Gavin to increase his weekly milage by 3.5 miles every week. If Gavin sticks to the plan, how many miles would he be expected to run during his 11th week of the training plan? Round to the nearest tenth (if necessary).

Step-by-step explanation:

In the first week of his running plan,the number of miles covered = 5 miles

Weekly mileage will increase by 3.5 miles every week.

At the end of second week, the number of miles covered = 5 + 3.5 = 8.5

At the end of third week, the number of miles covered = 8.5 + 3.5 = 12

The series is 5, 8.5, 12, ...

Consider this as an AP, where a = 5, d = 3.5

By formula,  

Substituting the values in the above equation, we get

= 5 +(9)3.5

= 5 + 31.5

=36.5 miles.

Gavin would be expected to run during 36.5 miles during his 11th week of the training plan