Question

What is the cardinal number of the set {1/x}, where x is an integer greater than or equal to 4 and less than or equal to 9?

a) 5
b) 6
c) 4
d) 6

Answer 1

The cardinal number of the set {1/x}, with x ranging from 4 to 9, is six because there are six distinct integers in that range, leading to six unique elements in the set.

Step-by-step explanation:

The student is asking for the cardinal number of the set {1/x}, where x is an integer greater than or equal to 4 and less than or equal to 9. To find the cardinal number, we simply count the distinct elements in the set.

Since x can be any integer from 4 to 9, we have six possible values for x: 4, 5, 6, 7, 8, and 9. For each of these values of x, we have a corresponding unique value of 1/x. Thus, we have six unique elements in the set.

Therefore, the cardinal number of the set {1/x} under the given conditions is six (option b).