At the quarterly birthday party of Sherry, a baby boy, 40 persons chose to kiss him and 25 chose to shake hands with him. 10 persons chose to both kiss him and shake hands with him. How many persons turned out at the party?  Select
A) 35 B) 75 C) 55 D) 25 E) 45
Let n(A) = No. of persons who kissed Sherry = 40   n(B) = No. of persons who shook hands with Sherry = 25   and n(A ∩ B) = No. of persons who both shook hands with Sherry and kissed him = 10   Then, using the formula, n(A U B) = n(A) + n(B) - n(A ∩ B)   n(A U B) = 40 + 25 - 10= 
<gadget id="calculator">40 + 25 - 10</gadget>
<output>55</output>
55.   ANSWER:55
<result>C</result>
At the quarterly birthday party of Sherry, a baby boy, 40 persons chose to kiss him and 25 chose to shake hands with him. 10 persons chose to both kiss him and shake hands with him. How many persons turned out at the party?