Answer:
The correct answer is B. 10 packs.
Explanation:
1. Let's review the information provided to us to answer the question correctly:
Number of students = 28 in each class
Number of classes = 7
Number of adults = 12
Number of buying tickets per pack = 20
2. How many packs of tickets should Mr Rogers buy?
Let's find the number of tickets to the zoo necessary, this way:
Number of tickets = Number of classes * Number of students + Number of adults
Number of tickets = 7 * 28 + 12
Number of tickets = 196 + 12
Number of tickets = 208
If Mr. Rogers buys 10 packs, it will be enough for all the students and 4 teachers. Buying additional 8 individual tickets would be for sure less expensive than buying 20 packs, unless the group is planning a second visit later.
The correct answer is B. 10 packs.