Answer:
{1,3,5,7,9,11}
Step-by-step explanation:
B' stands for the complement of B.
B' means set elements in the universe that aren't in B.
Here is the universe:
U={1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,...}
(The dots mean it continues with that pattern forever and ever.)
And the elements we taking out:
B={13,15,17,19,21,23,...}
So we taking out the odd numbers from U that are odd and greater than or equal to 13. (The dots mean it continues with that pattern forever and ever.)
So B' is the set of natural odd numbers that are less than 13:
{1,3,5,7,9,11}