How many terms are there in 2, 4, 8, 16,..., 256? Choose the correct option:
A) 14
B) 11
C) 12
D) 10
E) 8
2, 4, 8, 16, ..., 256 is a G.P with a =2   and r =4/2= 
<gadget id="calculator">4/2</gadget>
<output>2</output>
2   Let the number of terms be n. Then   2 x 2 ^n-1= 256   or 2^n-1 =128 = 2^7   Thus n - 1 =7   n= 8   ANSW8R:8
<result>E</result>
How many terms are there in 2, 4, 8, 16,..., 256?