Question

A photography book has 60 two-sided pages of pictures, each of which is 1/40 inch thick, where each two-sided page is preceded by a protective 1/80 inch thick piece of paper, and each side of the book is bound by a 1/4 inch cover. What is the total thickness of the book?

Answer 1

3.5 inches

Explanation:

Given :

A photography book has 60 two-sided pages of pictures.

Thickness of each page is
`(1)/(40)`

Each two-sided page is preceded by a protective 1/80 inch thick piece of paper.

Each side of the book is bound by a 1/4 inch cover.

To Find: What is the total thickness of the book?

Solution :

Since each two sided page is preceded by a protective 1/80 inch thick piece of paper.

So, both sided preceded by a protective thick piece =
`2*(1)/(80)`

=
`(1)/(40)`

And Thickness of each paper
`(1)/(40)`

So, total thickness of paper :
`(1)/(40)+(1)/(40)`

`(2)/(40)`

Since there are 60 pages.

So, thickness of 60 pages =
`60*(2)/(40)`

= 3 inches

Now each side of the book is bound by a 1/4 inch cover

So, thickness of cover of both side =
`2*(1)/(4)`

=
`(1)/(2)`

Now total thickness of book = thickness of 60 pages + thickness of both side covers

=
`3+(1)/(2)`

=
`(7)/(2)`

Thus the thickness of the book is 7/2 inches .

Hence the total thickness of book is 3.5 inches