title: How to calculate number of virtual pages
body: <p>virtual adress size: 32 bits</p>
  
  <p>page size = 4K =2^12 bytes </p>
  
  <p>what is the number of pages? 
  i know the answer is (2^32)/(2^12) = 2^20 but why?</p>
  
  <p>i think it should be (2^32)/(2^15) because of the byte bit conversion (2^12)*(8)=2^15</p>