Step-by-step explanation:
the union of two sets is a new sets that contains all of the elements that are in at least one or two sets and written as (A U B)
while intersection of two sets is a new set that contains all of the elements in both sets and written as (A n B)
Answer:
287 books
Step-by-step explanation
there was already 239 books. when the problem mentoins that Mary ADDS MORE books to the shelf, the operation is addition.
239+48=287
3/5 ➗ 7/10
3/5 ✖️ 10/7
=30/35
=6/7
Answer: 562,5+315,75=878,25