MetaDesign Solutions interview question

1) sorting 2)java memory map(stack area and heap area) 3)i=5, then print {1,2,3,4} without using loops or recursion 4)given an array of size n-1, having natural numbers till n,find the missing number(array is not sorted). 5)immutability of string(reason) 6)concepts of sql, joins, scalability and other things