math
posted by mary .
Given the following sets, select the statement below that is true.
A = {r, i, s, k, e, d}, B = {r, i, s, e}, C = {s, i, r}
(Points : 2)
B ¼ A and B ¼ C
A ¼ C and C ¼ B
B º A and C ¼ A
C º A and B º C
A º B and C º B

For posts with mathematical symbols, please post with encoding Western ISO88591 (Firefox) or WesternEurope(ISO) (Internet Explorer).
The above post in Western ISO88591 is as follows:
Given the following sets, select the statement below that is true.
A = {r, i, s, k, e, d}, B = {r, i, s, e}, C = {s, i, r}
(Points : 2)
B ⊂ A and B ⊂ C
A ⊂ C and C ⊂ B
B ⊆ A and C ⊂ A
C ⊆ A and B ⊆ C
A ⊆ B and C ⊆ B
B ⊂ A means that every element found in B is found in A, but B≠A, i.e. B is a proper subset of A.
If B can equal A, the symbol ⊆ is used.
For example, elements in B are r,i,s and e. Each of the four elements are also found in A which has a higher cardinality than B. So B ⊂ A is true.
On the other hand, the cardinality of B is 4, while that of C is 3. So B⊂C is not possible. So the first statement is false.
You can continue this way, and post your results for checking if you wish.