If M = {x : 3 \(\leq\) x < 8} and N = {x : 8 < x \(\leq\) 12}, which of the following is true? i. 8 \(\in\) M \(\cap\) N ii. 8 \(\in\) M \(\cup\) N iii. M \...

If M = {x : 3 \(\leq\)  x < 8} and N = {x : 8 <  x \(\leq\) 12}, which of the following is true?

i. 8 \(\in\) M \(\cap\) N

ii. 8 \(\in\) M \(\cup\) N

iii. M \(\cap\) N = \(\varnothing\)

Answer Details

Let's first understand what M and N represent. M is a set of numbers x that are greater than or equal to 3 but less than 8, while N is a set of numbers x that are greater than 8 but less than or equal to 12. i. 8 is not in the set M because M only includes numbers less than 8. Similarly, 8 is not in the set N because N only includes numbers greater than 8. Therefore, 8 is not in the intersection of M and N, making option i false. ii. The union of M and N includes all the numbers in both sets. Therefore, the union of M and N would include all numbers greater than or equal to 3 but less than or equal to 12. 8 is included in this range, so it must also be in the union of M and N. Therefore, option ii is true. iii. The intersection of M and N includes all the numbers that are in both sets. However, M and N do not overlap since there are no numbers that are both greater than or equal to 3 and less than or equal to 12. Therefore, the intersection of M and N is an empty set, making option iii true. Therefore, the correct answer is option iii only.