In a group of 86 students, each student is registered for at least one of three classes – History, Math and English. Twenty-eight students are registered for History, twenty-three students are registered for Math, and forty-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?  Choose the correct answer:	A) 3	B) 10	C) 9	D) 8	E) 7
3 U B U C = 3 + B + C - 3B-BC-3C + 3BC   86 = 28 + 23+ 44 -3B-BC-3C +3 =&gt; 3B+BC+3C = 12   Exactly Two classes = 3B+BC+3C - 33BC = 12 -3*3= 
<gadget id="calculator">12 -3*3</gadget>
<output>3</output>
3   Hence 3
<result>A</result>
In a group of 86 students, each student is registered for at least one of three classes – History, Math and English. Twenty-eight students are registered for History, twenty-three students are registered for Math, and forty-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?