CHAPTER O
Chapter Zer o
In thi s chapte r w e hav e gathere d 2 5 simpl e problems . T o solv e the m yo u d o
not nee d anythin g bu t commo n sens e an d th e simples t calculationa l skills . Thes e
problems ca n b e use d a t session s o f a mathematical circl e to prob e th e logica l an d
mathematical abilitie s o f students, o r a s recreationa l questions .
* # #
Problem 1. A numbe r o f bacteri a ar e place d i n a glass . On e secon d late r eac h
bacterium divide s i n two , th e nex t secon d eac h o f th e resultin g bacteri a divide s
in tw o again , e t cetera . Afte r on e minut e th e glas s i s M L Whe n wa s th e glas s
half-full?
Problem 2 . Ann , John , an d Ale x too k a bu s tou r o f Disneyland . Eac h o f the m
must pa y 5 plastic chip s for th e ride , but the y hav e only plasti c coin s of values 10,
15, an d 2 0 chip s (eac h ha s a n unlimite d numbe r o f eac h typ e o f coin) . Ho w ca n
they pa y fo r th e ride ?
Problem 3 . Jac k tor e ou t severa l successiv e page s fro m a book . Th e numbe r o f
the first pag e he tore out wa s 183, and i t i s known that th e number o f the las t pag e
is written wit h th e sam e digit s i n som e order . Ho w man y page s di d Jac k tea r ou t
of the book ?
Problem 4 . Ther e are 24 pounds of nails in a sack. Ca n you measure out 9 pounds
of nails using onl y a balance wit h tw o pans? (Se e Figure 1.)
FIGURE 1
Problem 5 . A Caterpillar crawls up a pole 75 inches high, starting from the ground.
Each da y i t crawl s u p 5 inches, an d eac h nigh t i t slide s dow n 4 inches. Whe n wil l
it firs t reac h th e to p o f the pole ?
ï
http://dx.doi.org/10.1090/mawrld/007/01
Previous Page Next Page