$1.00) A baseball and bat together cost $1.10. The bat costs $1.00 more than the ball. What does the ball cost? 1 Ball + 1 Ball + $1.00 = $1.10 2 Balls + $1.00 = $1.10

$1.00) A baseball and bat together cost $1.10. The bat costs $1.00 more than the ball. What does the ball cost? 1 Ball + 1 Ball + $1.00 = $1.10 2 Balls + $1.00 = $1.10 2 Balls = 10¢

$1.00) A baseball and bat together cost $1.10. The bat costs $1.00 more than the ball. What does the ball cost? 1 Ball + 1 Ball + $1.00 = $1.10 2 Balls + $1.00 = $1.10 2 Balls = 10¢ 1 Ball = 5¢

• The possible combinations of ﬁve different birthdays: 365 × 365 × 365 × 365 × 365 (or 3655) • The ways you can select ﬁve birthdays without repeats: 365 × 364 × 363 × 362 × 361

in to the total possible events • Chance ﬁve people don’t share a birthday: (365 × 364 × 363 × 362 × 361) / (365 × 365 × 365 × 365 × 365) • Subtract from one to get the chance of the opposite occurrence (a birthday is shared)

has two children but not the gender of the children. A young girl answers the door, so that’s one child. What are the odds that the other child is a boy?

has two children but not the gender of the children. A young girl answers the door, so that’s one child. What are the odds that the other child is a boy? ⅔

The Wonder Years) • Sex symbol • Math degree (with honors) • Published author • Chayes-McKellar-Winn theorem Image from http://allinone1-z.blogspot.com/2010/12/danica-mckellar-hotdanica-mckellar.html

country average • 17 of those 34 countries score better than we do while only 5 score below us (11 are roughly even with us) • Ranking math proﬁciency from level 1 to level 6, only 27% of U.S. students score 4 or higher 2009 statistics for 15-year-olds from http://nces.ed.gov/surveys/pisa/pisa2009highlights_3.asp

entire heavens were covered.”—Genesis 7:19 NIV • 10,000 to 20,000 feet of water • “And rain fell on the earth forty days and forty nights.”—Genesis 7:12 NIV • 960 hours of rainfall • That’s water rising about 15 feet per hour

in my hand a list of 205— a list of names that were made known to the Secretary of State as being members of the Communist Party and who nevertheless are still working and shaping policy in the State Department."—Joe McCarthy, U.S. Senator

magna cum laude graduate, she majored in political science in college and was deeply involved in campus social affairs, especially in anti-discrimination and anti-nuclear issues. Which statement is more probable? (a) Judy works as a bank teller. (b) Judy works as a bank teller and is active in the feminist movement.

get elected • That’s because politicians use packing and cracking to distribute votes • Nick’s district looks like a dinosaur • The Voting Rights Act made this illegal, but only when racial (political is ﬁne)

$100 on coin ﬂips • The ﬁrst to win six ﬂips takes the pot • Their game is interrupted when the score is ﬁve to three • How do we fairly divide the pot?

wins since he’s leading and the prize is all or nothing • Payout ⅝ and ⅜ of the pot for their respective wins • Pay ⅞ and ⅛ for the odds each man will win (½ × ½ × ½ = ⅛ and 1 - ⅛ = ⅞)

patients for a disease. On average one in a 100 will have the disease. Can you ﬁnd those that have the disease by doing less than 100 tests? (Givens: you have enough of each patient’s blood to test them several times and you can test multiple patients at once by combining samples.)

choose to look up a new word when they ﬁrst encounter it • It’s an equally good idea to look up new math when you encounter it • http://www.wolframalpha.com/ • Ask a math geek

i)m - 1) B = L(1 + i)m - (1 + i)p) / ((1 + i)m - 1) P = Monthly payment L = Loan amout i = Monthly interest (6% loan: 0.06 / 12 = 0.005) m = Length of the loan in months B = Balance remaining p = Payments made