Question

Carla began a running program to prepare for track try-outs. On her first day she ran 3 miles, and on her second day she ran 5 miles. Since then, Carla has run 7 miles each day. If her log book shows that Carla has run 99 miles, for how many days has Carla been running 7 miles?

Answer 1

Given :

She run 3 miles 1 st day .

She run 5 miles 2 nd day .

Then she runs 7 miles per day .

To Find :

If she total runs 99 miles , for how many days has Carla been running 7 miles.

Solution :

The relation between total miles run and number of days she run 7 miles is :

$D=7n+3+5$

Putting , D = 99 miles , we get :

$7n+8=99\\\\n=\dfrac{91}{7}\\\\n=13$

From 13 days she is running 7 miles in a day .