Question 1132149

{{{ 2828 }}}
{{{1212}}} 
{{{ 100100}}}=> seems to be all numbers are doubled


I guess your numbers are {{{28}}},{{{12}}}, and {{{100}}}


{{{ 28 + 12d }}} is the number of shells she has after {{{ d }}} days


the number of days it will take for her to have over {{{ 100 }}} shells is found by solving:

{{{  28 + 12d > 100 }}}


Subtract {{{ 28 }}} from both sides:

{{{  28-28 + 12d > 100 -28}}}

{{{ 12d > 72 }}}

{{{ d > 72/12 }}}

{{{ d > 6 }}}


This means she won't have more than {{{100}}} shells until the {{{7}}}th day.