Teachers and students of a certain school plant trees in the suburbs. It is known that the number of teachers is 1/3 of the number of students. If each boy plants 13 trees, each girl plants 10 trees, and each teacher plants 15 trees, they will plant a total of 201 trees, how many teachers are there?
某校师生到郊外植树，已知老师人数是学生人数的(1/3)，如果每位男生种13棵树，每名女生种10棵树，每位教师种15棵树，他们一共种201棵树，那么老师有多少人？
<result>4</result>