A business school club, Friends of Foam, is throwing a party at a local bar. Of the business school students at the bar, 40% are first year students and 60% are second year students. Of the first year students, 45% are drinking beer, 30% are drinking mixed drinks, and 25% are drinking both. Of the second year students, 30% are drinking beer, 30% are drinking mixed drinks, and 20% are drinking both. A business school student is chosen at random. If the student is drinking beer, what is the probability that he or she is also drinking mixed drinks?  Options:
A) 2/5	B) 4/7	C) 11/18	D) 17/24	E) 17/10
Suppose there are 100 students   Group A : 40% = 40 students   45% drink beer = 18   30% mixed = 12   25% both = 10   Group B 60% = 60   30% beer= 18   30% mixed = 18   20% both= 12   now we need both ( beer + mixed = both)   probability = total beer drinker = 18+18= 
<gadget id="calculator">18+18</gadget>
<output>36</output>
36 and both= 20   thus 22/36 = 11/18   Hence 11/18
<result>C</result>
A business school club, Friends of Foam, is throwing a party at a local bar. Of the business school students at the bar, 40% are first year students and 60% are second year students. Of the first year students, 45% are drinking beer, 30% are drinking mixed drinks, and 25% are drinking both. Of the second year students, 30% are drinking beer, 30% are drinking mixed drinks, and 20% are drinking both. A business school student is chosen at random. If the student is drinking beer, what is the probability that he or she is also drinking mixed drinks?