The ratio of teachers to students at a school is 3: 74. there are 2,500 students at the school. about how many teachers are at the school?
a) 35

b) 100

c) 300

d) 600

      
                                   Teachers / Students  =  3 / 74

                                      Teachers  /  2,500  =  3 / 74

To solve a proportion,
you cross-multiply:            Teachers x 74  =  2,500 x 3

Divide each side by  74 :     Teachers  =  2,500 x 3 / 74

                                                                  =  101.4     ===>  101 teachers