-- If the spinner is honest and the sections are all the same size, then
each section should have an equal chance of being landed on.
-- If there are 4 sections, then the chance of landing on each one
should be 1/4 or 25%.
-- The chance doesn't depend on how many times you try it.
If there are 4 sections, then each one should come up
25% of the time.
The formula of the area of the circle is
Area = pi * (d/2)^2
So using the formula,
Area = 3.14 * (30/2)^2
Area = 3.14 * 15^2
Area = 706.5 ft^2
So the area of the hockey rink is 706.5 ft^2
Answer:
7 quarters, 8 nickels
Step-by-step explanation:
So the system of equations you have is:
x + y = 15
0.25x + 0.05y = 2.15
Here's how to solve:
first, multiply both sides of the equation 0.25x + 0.05y = 2.15 by 100 to get rid of the decimal places:
25x + 5y = 215
Then, you can divide both sides by 5 to simplify it more:
5x + y = 43
Now, you have the system of equations:
5x + y = 43
x + y = 15
Now subtract the two equations:
4x = 28
divide both sides by 4
x = 7
plug x = 7 into the equation x + y = 15 to solve for y:
7 + y = 15
subtract 7 from both sides
y = 8
So you know that there are 7 quarters and 8 nickels.