In a particular region, car registration plates consist of 4 letters and 2 digits. Numbers can be repeated but letters cannot. How many different registration plates can be issued?

1. Em uma fábrica de potes de plastico, observou-se no controle de qualidade que 1 em cada 10 potes apresentava algum tipo de defeito. Qual a probabilidade de escolher um pote aleatoria- mente dessa fábrica e ele não possuir defeito algum?

1 Para crear una prueba, un profesor tiene un banco de 50 preguntas. Si de ellas escogerá 20. ¿de cuántas formas puede crear la prueba? \( =50 \) \( =20 \)

Question 2 A bag contains 4 red balls, 3 black balls, and 3 green balls. Two balls are randomly drawn from the bag one after the other with replacement. 2.1 Construct a tree diagram to represent all possible outcomes of drawing two balls in succession. Clearly label the branches with the corresponding probabilities.

Question A professor gives a surprise quiz with one multiple choice question. There are 4 answer possibilities: B, C, and D. What is the probability that you randomly guess and select the correct answer? Give your answer as a fraction.

Question You roll a standard die (with the numbers \( \{1,2,3,4,5,6\} \) on its faces). Let \( A \) be the event that you roll an odd number. What is the probability of the event \( A \) ? Give your answer as a simplified fraction.