Descrete Mathematics

:In a recent survey, 200 students had undergraduate degrees in arts, 95 had undergraduate degrees in science and 120 had graduate degrees. Art undergrads with graduate degree totaled 55 while 40 science undergrads also had graduate degrees. Some students had multiple degrees, 25 had both art and science undergraduate degrees while 5 had both art and science undergraduate degrees with a graduate degree. The number of students with only a science degree was