That is, teachers and classmates * * * water flowers 300- 1=299 pots, and each person waters flowers on average;

But 299= 13×23.

So there are 13 or 23 people;

And 13- 1= 12 can be divided into three groups on average; 23- 1=22 cannot be divided into three groups equally;

So there are 13 people, and each person waters 23 pots of flowers on average;

Teacher Wang watered 23+ 1=24 pots of flowers.