4 professors and 6 students are being considered for membership on a supervisory committee which must consist of 3 people. If the committee has to include at least 1 professor, how many ways can this committee be formed? Choose the correct choice from the following answers:  A) 36  B) 60  C) 72  D) 80  E) 100
combinations:   1 professor 2 students   students: 6 x 5 / 2 = 15   15*4= 
<gadget id="calculator">15*4</gadget>
<output>60</output>
60   2 professors 1 student   4 x 3 / 2= 6   6*6= 
<gadget id="calculator">6*6</gadget>
<output>36</output>
36   3 professors     4/1= 
<gadget id="calculator">  4/1</gadget>
<output>4</output>
4   60 + 36 + 4= 
<gadget id="calculator">60 + 36 + 4</gadget>
<output>100</output>
100   ANS:100
<result>E</result>
4 professors and 6 students are being considered for membership on a supervisory committee which must consist of 3 people. If the committee has to include at least 1 professor, how many ways can this committee be formed?