need quick help

5) Suppose that an urn initially contains five balls, numbered 1 thorugh 5. Suppose that these balls will be sequentially drawn at random, without replacement, and a success will be considered to occur if the number drawn on draw i (i = 1, 2,...,5) is the largest number drawn so far. (So if the balls are drawn in the order 2, 1, 5, 3, 4, then successes occur on draws 1 and 3, and if they are drawn in the order 1, 2, 3, 4, 5, then all five draws result in a success.) Letting X be the number of success that occur in the 5 draws, give the expected value of X. (Hints: Express X as a sum of binary indicator random variables. Use a symmetry argument to determine the probability of success on each draw.)