Prob Divisible 7 11
1. The problem asks for the probability that an integer chosen from the set $\{1, 2, 3, \ldots, 500\}$ is divisible by 7 or 11.
2. Use the formula for the probability of the union of two events:
$$P(7 \text{ or } 11) = P(7) + P(11) - P(7 \text{ and } 11)$$
3. Calculate the number of integers divisible by 7:
$$\left\lfloor \frac{500}{7} \right\rfloor = 71$$
4. Calculate the number of integers divisible by 11:
$$\left\lfloor \frac{500}{11} \right\rfloor = 45$$
5. Calculate the number of integers divisible by both 7 and 11 (i.e., divisible by $7 \times 11 = 77$):
$$\left\lfloor \frac{500}{77} \right\rfloor = 6$$
6. Calculate the total count divisible by 7 or 11:
$$71 + 45 - 6 = 110$$
7. The total number of integers in the set is 500, so the probability is:
$$\frac{110}{500} = \frac{11}{50}$$
8. Therefore, the probability that a randomly chosen integer from 1 to 500 is divisible by 7 or 11 is $\boxed{\frac{11}{50}}$.