Fro the question, we are given the following information;
Number of male teachers = 15 male teachers
Number of female teachers = 35 female teachers
Required
The ratio of FEMALE teachers to male teachers
Ratio means division
Ratio = femaile teacher/male teachers
Ratio = 35/15
Ratio = (5*7)/(5*3)
Ratio = 7/3
Hence the ratio of the FEMALE teachers to male teachers is 7:3