![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
The student can read 7 pages of a book in 10 minutes.
\The ratio of pages to minutes is ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=28132d442e0d9148497ad3bf3ef82309.png\")
.
Let x is the number of pages.
\The student can read x pages of a book in 30 minutes.
\The ratio of pages to minutes is ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=604d1441fb36e75f9d243f8688861f09.png\")
.![\"\"](\"/userfiles/image/steps_images/step2.JPG\")
Therefore proportion is ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=0ac4054662ae0e919de748025a7a8ffd.png\")
.
Multiply each side by ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=52ecd403abcb215610fbd3e06f9dde74.png\")
.
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=4794878f6a59bdab23893dca52eb7de6.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=750e0fafe381e8daf5a34e2450175731.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=62294e2a1820ebe7110c58fac6dff1d9.png\")
.![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
The number of pages is 21.