The school librarian ordered new books. Of the books 1/3 are science 2/5 are biographies and the rest are fictio. What fraction of the books ordered are fiction?

Answer 1

fraction of fictional books = 1-1/3 -2/5

= 1 - 5/15 - 6/15

= 1-11/15

= 15/15 -11/15

= 4/15 = the fraction of books ordered that are fiction

or you could try to solve the problem converting to decimals then back to fraction at the end

1/3 = .3333.....

2/5 = .4

1 - .333... -.4

= 1- .7333...

= .2666....

= 4/15

that's a little more difficult though, but a check on the answer, use a calculator, 4 divided by 15 = .2666....

or your calculator may truncate it to something like .2667 or .26667 or .27 as it often rounds off to nearest decimal

x = .26666....

10x = 2.6666...

10x -x = 2.4

9x = 2.4

x = 2.4/9

= 24/90

divide numerator and denominator by 3

= (24/3)/(90/3)

= 8/30

divide numerator and denominator by 2

= 8/2)/(30/2)

= 4/15 as fraction

= .2666....