Ex 15.1, 12

Transcript

Ex15.1, 12 A game of chance consists of spinning an arrow which comes to rest pointing at one of the numbers 1, 2, 3, 4, 5, 6, 7, 8 (see the given figure), and these are equally likely outcomes. What is the probability that it will point at 8? Total numbers = 8 Number of times we can get 8 = 1 Probability of getting 8  = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑖𝑚𝑒𝑠 𝑤𝑒 𝑐𝑎𝑛 𝑔𝑒𝑡 8)/(𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟𝑠) = 1/8 Ex15.1, 12 (ii) Odd number? Total numbers = 8 Odd numbers that can be the outcome = 1, 3, 5, 7 Number of odd number = 4 Probability of getting odd number = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑜𝑑𝑑 𝑛𝑢𝑚𝑏𝑒𝑟)/(𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟𝑠 ) = 4/8 = 1/2 Ex15.1, 12 (iii) Number greater than 2? Total numbers = 8 Number greater than 2 = 3, 4, 5, 6, 7, 8 Number of numbers greater than 2 = 6 Probability of getting number greater than 2  = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑛𝑢𝑚𝑏𝑒𝑟𝑠 𝑔𝑟𝑒𝑎𝑡𝑒𝑟 𝑡ℎ𝑎𝑛 2)/(𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟𝑠 ) = 6/8 = 3/4 Ex15.1, 12 (iv) Number less than 9? Total numbers = 8 Number less than 9 = 1, 2, 3, 4, 5, 6, 7, 8 Number of number less than 9 = 8 Probability of getting number less than 9  = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑛𝑢𝑚𝑏𝑒𝑟𝑠 𝑙𝑒𝑠𝑠 𝑡ℎ𝑎𝑛 9)/(𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟𝑠 ) = 8/8 = 1