Tuan rode in a 40m mile bike race

what fraction of the race had tuan ridden when completed 25 miles?

25/40 = 5/8

To find the fraction of the race that Tuan had ridden when he completed 25 miles, we need to compare the distance he has ridden to the total distance of the race.

Let's break it down step by step:

1. Calculate the fraction by dividing the distance Tuan has ridden by the total distance of the race.
Fraction = Distance ridden / Total distance

In this case, Tuan has completed 25 miles, so the distance ridden is 25 miles. We are given that the race is 40 miles. Therefore, the fraction can be calculated as follows:
Fraction = 25 miles / 40 miles

2. Simplify the fraction (if necessary). In this case, the fraction cannot be simplified further, so we have:
Fraction = 25/40

So, Tuan had ridden 25/40 of the race when he completed 25 miles.