En las matematicas para que concepto se usan las letras?

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

The parabola x= √y-9 opens: a.)up b.)down c.)right d.)left

What is the measure of the smallest angle in the diagram? 15 29 32 45