In a group of 68 students, each student is registered for at least one of three classes – History, Math and English. Twenty-five students are registered for History, twenty-five students are registered for Math, and thirty-four students are registered for English. If only three students are registered for all three classes, how many students are registered for exactly two classes?
1. 13
2. 10
3. 9
4. 8
5. 7
How many students?
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- givemeanid
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Is it 10 ?
H + M + E - HM - ME - HE - 2*MHE = 68
Therefore HM + ME + HE = 25 + 25 + 34 - 2*3 - 68 = 78 - 68 = 10
Please note that you have to include 2*MHE as you have counted the
trio combo 3 times in H + M + E.
H + M + E - HM - ME - HE - 2*MHE = 68
Therefore HM + ME + HE = 25 + 25 + 34 - 2*3 - 68 = 78 - 68 = 10
Please note that you have to include 2*MHE as you have counted the
trio combo 3 times in H + M + E.
- givemeanid
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