Khalil has a game board as shown below, which is a square with 20-cm sides. The area of the largest circle is 314 square centimeters.
3 concentric circles inside of a green square. The largest circle is labeled 1, the next circle is labeled 3, and the smallest circle is labeled 5.
What is the probability of scoring 1, 3, or 5 points with one randomly thrown dart?
50%
62.5%
75%
78.5%
The total area of the square is 20 cm x 20 cm = 400 square cm.
The area of the largest circle (score of 1) is 314 square cm.
The area of the next circle (score of 3) is 196 square cm.
The area of the smallest circle (score of 5) is 78.5 square cm.
The total area of the circles is 314 + 196 + 78.5 = 588.5 square cm.
Therefore, the probability of scoring 1, 3, or 5 points with one randomly thrown dart is:
588.5 / 400 = 1.47
So, the correct answer is 78.5%.