Answer:
<h2>4</h2>
Step-by-step explanation:

Answer:
3.14 = pi
1.) R = 1.5 and A = 7.065
2.) D = 28 and A = 615.44
3.) R = 10 and A = 314
Step-by-step explanation:
R = 0.5×d
Area of circle = π×r²
Answer:
x = friends that paid discount price = 8
y = friends that paid regular price = 4
Step-by-step explanation:
Let
x = friends that paid discount price
y = friends that paid regular price
x + y = 12 (1)
6x + 8y = 80 (2)
From (1)
x = 12 - y
Substitute x = 12 - y into (2)
6x + 8y = 80 (2)
6(12 - y) + 8y = 80
72 - 6y + 8y = 80
- 6y + 8y = 80 - 72
2y = 8
y = 8/2
y = 4
Substitute y = 4 into (1)
x + y = 12 (1)
x + 4 = 12
x = 12 - 4
x = 8
x = friends that paid discount price = 8
y = friends that paid regular price = 4
12%
$68 - 59.9 = $8.1
$8.1/$68 = 0.11911764705
0.11911764705 x100 = 11.911764705
11.911764705 is rounded up to 12
12%