Answer:
A or 2
Step-by-step explanation:
r · 7 ≤ 21 [r multiplied by 7 is less than or equal to 21]
7r ≤ 21
[If you wanted to solve it]
7r ≤ 21 Divide 7 on both sides to get "r" by itself

r ≤ 3
The new cost would be 19.55.
Explanation: 1. 23 * 0.15 = 3.45
2. 23 - 3.45= 19.55
6 units
12 is also a diameter because it goes through the whole circle.
Divide it by 2 to find 6.