A paper has two sections of 5 questions each. A student must answer 4 questions, taking at least one from each section. In how many ways can the student choose?
Correct answer A. 200
Explanation
All choices = 10C4 = 210. Choosing all 4 from one section = 5C4 + 5C4 = 10. Valid choices = 210 - 10 = 200.
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Discussion