Question 1070987
Let {{{ N }}} = number of books received
{{{ n }}} = number of books that are paid for
{{{ N = n + n/2  }}}
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{{{ n = 16 }}}
{{{ N = 16 + 16/2 }}}
{{{ N = 16 + 8 }}}
{{{ N = 24 }}}
( note that {{{ n }}} must be even, or else you
ignore half-books when {{{ n }}} is odd )