To find out how many bottles of water the runners drank, we can subtract the number of bottles left after the run from the total number of bottles donated.
Total bottles donated = 750 Bottles left after the run = 89
Now, we perform the subtraction:
Bottles drank = Total bottles donated - Bottles left Bottles drank = 750 - 89 Bottles drank = 661
Therefore, the runners drank 661 bottles of water.