A department store employs 28 high school students, all juniors and seniors. Six of the 12 senoirs are females and 12 of the juniors are males. On student employee is chosen at random. What is the probability of selecting a senoir or female?
P(Senior or Female) = P(Senior) + P(Female) - P(Senior and Female)
P(Senior or Female) = 12/28 + 10/28 - 6/12 = 16/28 = 4/7
