A mother and father have seven children, and the family receives an invitation with four tickets to the circus. If the family decides to randomly select the four members who get to attend the circus, but determine that the chosen group must include at least one of the mother and father, how many different groups are possible to send to the circus?
Choose the correct choice:
A) 70  B) 84  C) 91  D) 108  E) 126
Condition 1: Atleast one of the mother and father along with seven children must be selected   Then either - Mother or father = 2C1 = 2 ways for one ticket and 7C3 = 35 ways for other three tickets. Total ways here is   2*35= 
<gadget id="calculator">  2*35</gadget>
<output>70</output>
70   Condition 2: Both M and F selected and this is 1 way...then we'll have only two tickets for 7 children..then we can select 7C2= 21.   Total 70+21= 
<gadget id="calculator">70+21</gadget>
<output>91</output>
91.   Option 91.
<result>C</result>
A mother and father have seven children, and the family receives an invitation with four tickets to the circus. If the family decides to randomly select the four members who get to attend the circus, but determine that the chosen group must include at least one of the mother and father, how many different groups are possible to send to the circus?