Question

The thickness of a book varies directly with

the number of pages in the book. A book is
1.8 cm thick and contains 350 pages. What is
the thickness of the first 84 pages of the book?

Answer 1

`\qquad \qquad \textit{direct proportional variation}\\\\\textit{\underline{y} varies directly with \underline{x}}\qquad \qquad \stackrel{\textit{constant of variation}}{y=\stackrel{\downarrow }{k}x~\hfill }\\\\\textit{\underline{x} varies directly with }\underline{z^5}\qquad \qquad \stackrel{\textit{constant of variation}}{x=\stackrel{\downarrow }{k}z^5~\hfill }\\\\[-0.35em]~\dotfill`

`\stackrel{\textit{`