Simple Probability PDF

Topic: Simple probability Question: Which spinner has a 1/4 probability of landing on red? Hint: Consider the size of each section, not just the number of sections in each spinner. Answer choices: A B C D All of the spinners have a 1/4 probabi...

Topic: Simple probability Question: Which spinner has a 1/4 probability of landing on red? Hint: Consider the size of each section, not just the number of sections in each spinner. Answer choices: A B C D All of the spinners have a 1/4 probability of landing on red. 121 Solution: D To find the probability of the octagon spinner landing on red, consider that the triangles are the same size and shape. This means there are 2 out of 8 total ways to land on red. 2 1 P(red) = = 8 4 To find the probability of the circle spinner landing on red, consider that the red parts each make up 1/8 of the circle, since they are half of a quarter of the circle. We have 2 of them, so 2 1 P(red) = = 8 4 To find the probability of the square spinner landing on red, consider that it’s divided into 4 equal triangles, one of which is red. 1 P(red) = 4 122 Topic: Simple probability Question: Brett bought a box of chocolates. 2 of them are coconut, 3 are orange, 4 are caramels, and 1 is raspberry. All of the chocolates look the same. What’s the probability that Brett chooses a coconut chocolate? Answer choices: A 20 % B 30 % C 50 % D 60 % 123 Solution: A To answer the question, use the definition of simple probability. outcomes that meet our criteria P(event) = all possible outcomes In this case, the outcomes that meet our criteria are the 2 coconut chocolates. All possible outcomes can be found by adding all of the types together. 2 + 3 + 4 + 1 = 10 Therefore, the probability of choosing a coconut chocolate is 2 1 P(coconut) = = = 0.2 = 20 % 10 5 124 Topic: Simple probability Question: Linel is playing the game Go Fish with her daughter Leah. She needs a picture of a blue whale to win the game. In the pile there are 4 whales, 6 tuna fish, 1 dolphin, and 3 mackerel. To the nearest percent, what is the probability that she draws a whale and wins the game? Answer choices: A 7% B 18 % C 35 % D 29 % 125 Solution: D Remember the definition of simple probability. outcomes that meet our criteria P(event) = all possible outcomes In this case, the outcomes that meet our criteria are the 4 whales. All possible outcomes can be found by adding all of the types of cards in the deck together: 4 + 6 + 1 + 3 = 14 Therefore, the probability of pulling a whale from the deck is 4 P(whale) = ≈ 0.29 ≈ 29 % 14 126