What should I do in this situation?

[Tyler S.]

I am assigning my contract on a property. I scheduled one buyer at 1 o clock on wed to see the house who might pay $46,500. I have one more buyer coming to see the house at 2 o clock wed who might pay $47,000. If buyer number one wants to buy, should I cancel buyer # 2 an hour early on account of first come first serve or should I wait to see if buyer # 2 wants it and if he/she does then then which one should I take?