Answer:
Total = 686000 meters for 10 weeks 7 days a week.
Step-by-step explanation:
Let's solve this by doing the increase on just 1 training day per week. Then we can find the grand total for 7 days a week by multiplying by 7
a = 8000
n = 10
d = 400
Sum = (a + L)*n/2
Sum = (8000 + 11600)*10/2
Sum = 19600 * 10/2
Sum = 98000 meters.
This total represents 1 training day a week.
The total amount is 7 times this figure.
Total = 7 * 98000 = 686 000 meters.