For each of the five questions in this exercise, only one of the four proposed answers is correct. No justification is required. A wrong answer, a multiple answer or the absence of an answer to a question neither awards nor deducts points.
We consider L a list of numbers consisting of consecutive terms of an arithmetic sequence with first term 7 and common difference 3, the last number in the list is 2023, namely: $$\mathrm{L} = [7, 10, \ldots, 2023].$$
Question 1: The number of terms in this list is:
| Answer A | Answer B | Answer C | Answer D |
| 2023 | 673 | 672 | 2016 |
Question 2: We choose a number at random from this list. The probability of drawing an even number is:
| Answer A | Answer B | Answer C | Answer D |
| $\frac{1}{2}$ | $\frac{34}{673}$ | $\frac{336}{673}$ | $\frac{337}{673}$ |
We choose a number at random from this list. We are interested in the following events:
- Event $A$: ``obtain a multiple of 4''
- Event $B$: ``obtain a number whose units digit is 6''
We are given $p(A \cap B) = \frac{34}{673}$.
Question 3: The probability of obtaining a multiple of 4 having 6 as the units digit is:
| Answer A | Answer B | Answer C | Answer D |
| $\frac{168}{673} \times \frac{34}{673}$ | $\frac{34}{673}$ | $\frac{17}{84}$ | $\frac{168}{34}$ |
Question 4: $P_B(A)$ is equal to:
| Answer A | Answer B | Answer C | Answer D |
| $\frac{36}{168}$ | $\frac{1}{2}$ | $\frac{33}{168}$ | $\frac{34}{67}$ |
Question 5: We choose, at random, successively, 10 elements from this list. An element can be chosen multiple times. The probability that none of these 10 numbers is a multiple of 4 is:
| \begin{tabular}{ c } Answer A |
| $\left(\frac{505}{673}\right)^{10}$ |
&
| Answer B |
| $1 - \left(\frac{505}{673}\right)^{10}$ |
&
| Answer C |
| $\left(\frac{168}{673}\right)^{10}$ |
&
| Answer D |
| $1 - \left(\frac{168}{673}\right)^{10}$ |
\hline \end{tabular}