Tuesday, February 11, 2014

When a book is opened and the page numbers multiplied the product is 2,970. What was the numbers of the pages?

well if you open a book, you will find that the two pages
in front of you will be consecutive


Given that the two
pages are consecutive


let the first page be page
X


then the second page is page
x+1


By definition of
multiplication


X(X+1)=2970


X^2+X-2970=0


well
this needs some factoring


first we see there is a 5 in a
2970 (obvious)


2970/5=594


i
see a two in the
number


594/2=297


2+9+7= 18
thats a multiple of 3


297/3=99 which is still a multiple of
3


99/3= 33 which is still a multiple of
3


33/3=11 Youa re left with a prime
number


so it is
5,2,3,3,3,11


you need to form two numbers that the
difference is one


by calculation, we find
out


5*11 = 55


2*3*3*3=
54


so the factoring is
(X+55)(X-54)=0


I dont know a book that has negative page
numbers


X= 54


so the two pages
are 54 and 55

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