In a friendship gang Andrew has 8 gang, in how many ways can he invite one or more of the gang to his house?  Choices:
A) 245
B) 255
C) 260
D) 267
E) 278
Andrew can select one or more than one of his 8 gang.   =&gt; Required number of ways = 28 – 1= 255.   255
<result>B</result>
In a friendship gang Andrew has 8 gang, in how many ways can he invite one or more of the gang to his house?