In how many ways can you sit 8 people on a bench if 4 of them must sit together?	Select: A) 720 B) 2,160 C) 2,880 D) 4,320 E) 40,320
In such questions, always tie the person that have to sit together. So we have effectively 4+1= 
<gadget id="calculator">4+1</gadget>
<output>5</output>
5 persons to arrange.   They can be arranged in 5! ways.   Now the 4 persons can themselves be arranged in 4! ways.   Total ways: 5!*4!= 2880.   2,880 is the answer.
<result>C</result>
In how many ways can you sit 8 people on a bench if 4 of them must sit together?