In an examination, 70% of the students passed in Paper I, and 60% of the students passed in Paper II. 15% of the students failed in both papers while 270 students passed in both papers. What is the total number of students

In an examination, 70% of the students passed in Paper I, and 60% of the students passed in Paper II. 15% of the students failed in both papers while 270 students passed in both papers. What is the total number of students?