Question 8 - End-of-Chapter Exercises - Chapter 7 - The Mathematics of Maybe: Introduction to Probability

Transcript

Question 8 (i) The letters of the word ‘PEACE’ are placed on cards. Leela draws a card without looking. (i) What is the probability that it is a P, E or C? Now, Total letters = 5 Since there are 1 P, 1 A, 1 C and 2 E Letters if it’s a P, E or C = 4 Now, Probability that it is a P, E or C = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑙𝑒𝑡𝑡𝑒𝑟𝑠 𝑖𝑓 𝑖𝑡𝑠 𝑎 𝑃, 𝐸 𝑜𝑟 𝐶)/(𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑙𝑒𝑡𝑡𝑒𝑟𝑠) = 𝟒/𝟓 Question 8 (ii) The letters of the word ‘PEACE’ are placed on cards. Leela draws a card without looking. (ii) What is the probability that it is not an E? Now, Total letters = 5 Number of letters not E = Number of letters of P, A or C = 3 Now, Probability that it is not E = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑙𝑒𝑡𝑡𝑒𝑟𝑠 𝑖𝑓 𝑖𝑡𝑠 𝑛𝑜𝑡 𝐸)/(𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑙𝑒𝑡𝑡𝑒𝑟𝑠) = 𝟑/𝟓