Alejandro and pedro are riding their bike to school. after 1 mile, the are 5/8 of the way there. how much farther do they have to go?

1 / (5/8) = x / 1...1 mile to 5/8 = x miles to 1
cross multiply
5/8x = 1
x = 1 / (5/8)
x = 1 * 8/5
x = 8/5 or 1 3/5 miles...total distance

and if they already rode 1 mile(1 3/5 - 1) = 3/5 of a mile left to go <==

C. i think it is step 3