Suppose an algorithm has O(2^n ) complexity, where n is the size of a problem which is solved using such an algorithm. Let n = 50 for a given problem. Lets say a current computer takes 1 micro-second to perform each operation. What fraction of the problem can it solve in 1 second? What size problem can a computer which is half as fast (i.e., each operation takes twice the time as the current computer) solve in 1 second using the same algorithm?