In an examination of 150 students, 70 passed in Science, 60 passed in Mathematics, and 50 passed in English. If 20 passed in both Science and Mathematics, 15 in Mathematics and English, 18 in Science and English, and 10 passed in all three subjects: (a) Represent the data in a single Venn diagram. (b) How many students failed in all three subjects? (c) Find the ratio of students who passed only in Science to those who passed only in Mathematics.