Two family reunions are happening at the same hotel, the Oates reunion and the Yellow reunion. All 100 guests at the hotel attend at least one of the reunions. If 42 people attend the Oates reunion and 65 people attend the Yellow reunion, how many people attend both reunions?  Choose the most appropriate option:
A) 2 B) 7 C) 10 D) 16 E) 22

Rationale: no of people in oates reunion = 42 no of people in yellow reunion = 65 attending both = x all guests attend at least one . therefore , 100 = 42 + 65 - ( both ) both = 7 answer b
Answer: B