A stockbroker dealt with 30 customers on a certain day. Of these, 12 bought and sold stocks and 17 sold stocks (but did not buy). How many of the customers bought stocks (but did not sell)?

These question are hard can you me with answers

Abaker makes 186 cookies. some are chocolate chip and some are oatmeal raisin, and both kinds are made with and without nuts, as shown in the table above. because they are more popular, the baker made 2/3 of the cookies chocolate chip. if a chocolate chip cookie is chosen at random, what is the probability that it will have nuts? a) 21/93 b) 21/62 c) 41/93 d) 21/41

Last one and the bottom answer choice is y=(x-4)^2+1 you guys!