One hundred businessmen gather at a meeting. 85 of them carry a cellular phone, 80 of them have a beeper, 75 of them speak at least two languages and 70 of them wear a suit. Therefore, a certain number of them have all of the above: a cell phone AND a beeper AND speak at least two languages AND wear a suit. Out of these 100 businesspeople, what is the least possible number who have all of the above?
Name:
Anonymous2007-10-04 12:13
btw, Answer is either 10, 15, 17, 18 or 20.
Name:
Anonymous2007-10-04 13:09
bump
Name:
Anonymous2007-10-04 13:15
100-((100-85)+(100-80)+(100-75)+(100-70))=10
To find the smallest number of people with all 4, we want to minimize overlap between the groups which are missing something; thus we assume that everyone has either 3 or all of the above. So we just add up the compliments and subtract from the initial group to get 10.