JHU-CTY Theory of Computation (TCOM) Lancaster 2007 ~ Instructors Kayla Jacobs & Adam Groce MATH REVIEW PROBLEMS (1) Simple Set Theory Fill in the blanks with , , , , =, or ≠: 42 _______ {2, 4, 6, 8, 10, …} 42 _______ {2, 4, 6, 8, 10} {42} _______ {2, 4, 6, 8, 10, …} _______ {42} _______ _______ 3/2 _______ 3/2 _______ 3/2 _______ {x | x is the answer to Life, the Universe, and Everything} (2) Combinations Fun How many 9-letter strings (that may or may not be actual English words) can you make by rearranging letters of the word KALAMAZOO? (Note: You can leave factorials in your answer.) (3) Prove It! a) Prove that 1 + 3 + 5 + 7 + … + (2n-1) = n2. What proof technique did you use? (continued) 1 JHU-CTY Theory of Computation (TCOM) Lancaster 2007 ~ Instructors Kayla Jacobs & Adam Groce (continued) b) Prove that there are at least two people at CTY Lancaster (population ~500) with the same birthday. What proof technique did you use? c) Prove that the cube root of 2 is irrational. What proof technique did you use? 2