Question 1057965
Let {{{ n }}} = the number of pages in the book
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He read {{{ ( 1/5)*n }}} on the 1st day,
so there are {{{ (4/5)*n }}} pages left
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On the 2nd day, he read
{{{ (5/8)*(4/5)*n = (1/2)*n }}}
So far he has read {{{ (1/5)*n + (1/2)*n = (7/10)*n }}}
There are {{{ (3/10)*n }}} pages left
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On the 3rd day, he read the remaining pages,
so I can say:
{{{ (3/10)*n = (1/3)*(3/10)*n + 16 }}}
{{{ (3/10)*n = (1/10)*n + 16 }}}
{{{ (3/10)n - (1/10)*n = 16 }}}
{{{ (1/5)*n = 16 }}}
{{{ n = 80 }}}
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There were 80 pages in the book
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check:
The 1st day he read {{{ (1/5)*80 = 16 }}} pages
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On the 2nd day, he read {{{ (5/8)*(4/5)*80 = 40 }}} pages
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So far he has read {{{ 16 + 40 = 56 }}} pages
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On the 3rd day, he read the remaining pages
{{{ 80 - 56 = (1/3)*( 80 - 56 ) + 16 }}}
{{{ 24 = (1/3)*24 + 16 }}}
{{{ 24 = 8 + 16 }}}
{{{ 24 = 24 }}}
OK
Hope I got it!