sorry, but it doesnt work like that here. we dont provide help to people who have not shown any effort so we need to see what you've tried and what your ideas are about such question before we consider helping you out...
seems like the question want you to derive the MLE for the parameters of a multinomial distribution. Actually it is a quite standard MLE problem - this time you will need to solve a system of (linear) equations as dimension of the parameter space. Remember the sum of the parameters is equal to 1. You may want to compare with the binomial case (with 2 categories but the dimension is 1).