In a survey of 100 students, the number studying French (F), German (G) and Spanish (S) is shown in the Venn diagram: the region where all three subjects overlap contains 5 students; the region for F and G only (not S) contains x students; the region for F and S only (not G) contains 8 students; the region for G and S only (not F) contains 6 students; the region for F only contains 20 students; the region for G only contains 15 students; the region for S only contains 2x students; and 10 students, outside all three circles, study none of the three languages.
Figure (to be drawn): A three-circle Venn diagram (circles F, G and S, all overlapping in the classic three-set arrangement) inside a rectangle labelled xi. Region values: all three = 5, F and G only = x, F and S only = 8, G and S only = 6, F only = 20, G only = 15, S only = 2x, outside all three circles = 10.
(a)Form an equation in x, and solve it to find the value of x.(3)
(b)Find the number of students who study Spanish.(3)
(c)Find the number of students who study at least two of the three languages.(2)
(d)A student is selected at random from the 100 students. Find the probability that the student studies exactly one of the three languages.(2)
(Total for Question 8 is 10 marks)