Answer:
72 pages
Explanation:
If each page holds 10 cards, then we find the number of pages needed, we just need to divide the number of postcards by how many fit on each page.
So 714/10=71.4, or 71 r4
Because we do not have a whole number, we need to add another page so the extra 4 postcards have a page.
Therefore Mariah need 72 pages to hold her 714 postcards.
Hope this helped!