In a friendship gang Raja has 9 gang, in how many ways can he invite one or more of the gang to his house?	Choose one:
A) 124 B) 587 C) 987 D) 511 E) 263
Raja can select one or more than one of his 8 gang.   =&gt; Required number of ways = 2^9 – 1= 511.   511
<result>D</result>
In a friendship gang Raja has 9 gang, in how many ways can he invite one or more of the gang to his house?