Easiest way is to find out first how many she runs in a week. For that you can multiply the number of hours she runs a weekday by 5. (3.2*5) That should be 16. Now, since you want to know how many miles she will run in a span of 6 weeks you must multiply it by 6 now. That is 96. Since you know that, let's move on to the weekends. It is 1.5 per weekend day or 3 per weekend. Now you have to multiply 3 by 6 because you want to know for six weeks. Since you have both your numbers now, 18 and 96, you can add them to make a final of 114.
The car goes 23.2 miles every gallon, so with 15 gallons (15 * 23.2 = 348) it can go 348 miles. With the extra .25 that the car has, it can go 0.25 * 23.2 = 5.8 miles. 348 miles plus the 5.8 miles gets you 353.8 miles on 15.25 gallons.
