In an 80 km biathlon, a competitor completes the bicycle leg in 2 hours and the running leg in 40 minutes. If the competitor cycles 20 km/h faster than he runs, at what speed does he cycle?
We know that the total distance d = 80km.
We also know that we cycle 2h at a v km/h velocity, and 2/3h (40min) at a (v-20)km/h velocity.
Then, we can say calculate the distance that we cycle and the distance that we run:
2hv km/h = km that we cycle
2/3h(v-20)km/h = km that we run
Then, since we know that the addition of both are the 80km... we can create an equation and solve it:
We must bare in mind that it is a very high velocity for a runner.