Assume that a hat contains four bills: a \( \$ 1 \), a \( \$ 5 \), a \( \$ 10 \), and a \( \$ 20 \) bill. Two bills are to be selected at random with replacement. Find the probability that both bills are \( \$ 10 \) it the second selected is a \( \$ 10 \) bill? The probability that both bills are \( \$ 10 \) if the second selected is a \( \$ 10 \) bill is (Simplify your answer. Type an integer or a fraction.)

1. Según estadísticas la probabilidad de que el motor de un auto nuevo de cierta marca sufra algún desperfecto en el primer año de uso es de 0.02 , si se prueban tres automóviles de esta marca, encuentre el número esperado de autos que no sufren de algún desperfecto en el primer año y su desviación estándar. Resultados \( \mu=2.94 \) y \( \sigma=0.2425 \)

In how many distinct ways can the letters of the word BELLE be arranged? 0 of 1

3. In a class of 100 students 75 are boys and 25 are girls. The chance that a boy gets a first class is 0.25 and the probability that a girl first class is 0.21 . find the probability that a student selected at random gets a first class. ( 3 marks )

In a group of people on holiday, it is established that there are: - 10 males under the age of 21 - 8 females under the age of 21 - 6 males aged between 21 and 30 - 5 females aged between 21 and 30 Calculate the probability that, if one person is selected at random from the group this person will be: \( \begin{array}{ll}\text { a) A male under the age of } 30 . \\ \text { b) A female. } \\ \text { c) A male over the age of } 21 . \\ \text { d) A person not older than } 21 . \\ \text { e) A male given that this person is over } 30 \text { years. } \\ \text { f) A female or between } 21 \text { and } 30 . \\ \text { g) A male or a female. }\end{array} \)

Question 10, 11.2.47 At a benefit concert, nine bands have volunteered to perform but there is only enough time for six of the bands to play. How many lineups are possible?