Answer:
- 27 hot dogs
- 13 bags of popcorn
Step-by-step explanation:
Had all received popcorn, the bill would have been 40×$1.75 = $70. The bill was $13.50 more than that. Each hot dog purchased in place of popcorn adds $0.50 to the bill, so the number of hot dogs must be ...
$13.50/$0.50 = 27
Of course, the remainder of the 40 items were popcorn, so 13 bags of popcorn.
27 hot dogs and 13 bags of popcorn were purchased.
"Formula of a circle" is too vague to be meaningful. Perhaps you meant, "Formula for the area of a circle in terms of its circumference."
The area of a circle in terms of its radius is A = πr^2. To put this formula to use, we have to know the radius of the circle. The circumference of a circle in terms of its radius is C = 2πr, so a formula for the radius is r = C / (2π).
Now let's find a formula for the area of a circle in terms of its circumference:
C C^2
A = πr^2 = π { ---------------- }^2 = ------------
2π 4π
or:
A = (C^2) / 4π
