8.13 is the answerer
ok so first put 2.5 over 1 since Marco ran 2.5 miles in hour, then put x over 3.25 since we dont know the miles he ran in 3.25, you cross multiply so, multiply 3.25 and 2.5, which is 8.125 (8.13) and since you have 1x you divide 1 by x which gets you X only and with the answer X=8.13!!!!