The answer is: the answer 19.6
Answer:
Step-by-step explanation:
Given that
Area of a circle 
Circumference of the circle 
Let us re-write the equation of area of circle:


Multiplying and dividing with 2:

Hence, <em>A</em> in terms of <em>C</em> can be represented as:

Answer:
Stefan originally paid $120 for the bicycle and helmet.
He made $72 by selling them to Jin.
Step-by-step explanation:
Given that:
Selling price of bicycle = $176
Selling price of helmet = $16
Total price = 176+16 = $192
This is 160% of what Stefan paid originally.
Let,
x be the original amount paid by Stefan.
160% of x = 192

Dividing both sides by 1.6

Original amount paid by Stefan = $120
Profit = 192 - 120 = $72
Hence
Stefan originally paid $120 for the bicycle and helmet.
He made $72 by selling them to Jin.