Flowers usually contain more stamen than pistils. Why do you think this is?

It only takes one pistil for seeds to be fertilized, but it doesn't guarantee that the pollen will find it way to the pistil. In insect pollinated plants, the insects may visit a different species next, so the pollen would go to the "wrong" type of plant. So by producing more stamens (and therefore more pollen) it increases the chances that at least some pollen gets to the "right" place.