In a class of 267 seniors, 94 study Spanish, 95 study Chemistry, 165 study Mathematics, 18 study Spanish and Chemistry, 75 study Chemistry and Math, 20 study Math and Spanish and 15 study all three subjects. Make a Venn diagram to illustrate the data and then find the probability that a student selected at random studies: a) either Chemistry or Math? b) neither Spanish nor Mathematics? c) at most 1 subject