Answer:
67 newsletters
Step-by-step explanation:
Each book of stamps hold 20 stamps. She has 3 whole books and 7/20 of a book
3 whole books with 20 stamps in each = 3*20 = 60 stamps
7/20 of a book means 7/20 of a book. We multiply this fraction by the total number of stamps in a book
7/20 * 20 = 7 stamps
The total number of stamps in 3 7/20 books of stamps is found by adding the number of stamps in the whole books plus the number of stamps in the fractional bool
60+7 = 67 stamps
She needs 1 stamp per newsletter, so she can mail 67 newsletters.
