Given:
Required:
To find the probability that the dart land will be in the shaded region.
Explanation:
Area of the circle is given by the formula:

Where r = radius
Thus the area of the circular region

The area of the square is given by the formula:

Thus the area of the given square

The probability of an event is given by the formula:

The probability that the dart land will be in the shaded region

Thus probability

Final answer:
Thus the probability that the dart land will be in the shaded region is 0.349.
-- The person in the audience will either win tickets or not win tickets.
-- The probability of (either win tickets or not win tickets) is 100%.
-- (Probability of win tickets) plus (probability of not win tickets) = 100%.
-- If (probability of win tickets) is 15%, then the (probability of not win tickets)
is the other 85%.
To solve for the A or the principal amount plus interest you can use two formulas:
A = P + I
Where: P = Principal
I = Interest
or you can use
A = P (1+ rt)
Where: P = principal
r = rate in decimal
t = time in years
With your given you can use the second one, without having to use the first.
Given that the Principal amount is $222 and the rate is 12% and time is 10 years, we first need to convert your rate into decimal by dividing the value in percent by 100 which will yield 0.12.
Then now we can just input the data that you know into the formula:
A = P(1+ rt)
= $222(1 + (0.12)(10))
= $222(2.2)
= $488.40
Your A is then equal to $488.40
If you need to get the simple interest all you need to use is the first formula given:
A = P + I
for the interest you transpose the P to the side of the A and you will get:
I = A - P
= $488.40 - $222
= $266.40
$266.40 is the added interest to the principal amount.