On Wednesday, mr. miles walked and ran 9/10 of the trail. Then he walked 1/8 of the trail back and stopped to rest. What fraction of the course was mr. Miles from the beginning of the trail when he stopped?

31/40 of the trail

Step-by-step explanation:

he completed 9/10 of the trail (or 72/80 because 9*8 is 72)

He went back 1/8 of the trail (or 10/80 because 1*10 is 10)

72-10 is 62

he went 62/80, simplified is 31/40 of the trail

Answer: 31/40 of the trail.

Step-by-step explanation:

At the start, he walked 9/10 of the trail.

Then, he backed 1/8 of the trail

The, the amount that he walked is:

d = 9/10 - 1/8

now, we must find a common multipler between 8 and 10, we know that 8*5 = 40 = 10*4

d = (4/4) * (9/10) - (5/5) * (1/8) = (4*9 - 5*1) / 40 = (36 - 5) / 40 = 31/40

So when he stops, he is at 31/40 of the trail.