<PRE><B>Question 1109622</B>
Let {{{ d }}} = the number of miles of the planned trip
{{{ d - (1/2)*d = (1/2)*d }}} is the distance left after
the 1st day
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{{{ (1/3)*(1/2)*d = (1/6)*d }}} was hiked on the 2nd day,
so, {{{ (3/6)*d - (1/6)*d = (1/3)*d }}} is left to hike
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{{{ (1/4)*(1/3)*d = (1/12)*d }}} was hiked on the 3rd day
so, {{{ (4/12)*d - (1/12)*d = (1/4)*d }}} is left to hike
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On the 4th day:
{{{ 3 = (1/5)*(1/4)*d }}}
{{{ 3 = (1/20)*d }}}
{{{ d = 60 }}}
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After the 4th day, She had hiked {{{ d - (1/4)*d = (3/4)*d }}}
plus {{{ 3 }}} = {{{ (3/4)*d + 3 }}} miles
{{{ (3/4)*60 + 3 = 48 }}}
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She hiked 48 miles during the 4 days
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check the answer:
{{{ d = 60 }}}
The 1st day, she hiked 30 mi with 30 mi left
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The 2nd day, she hiked {{{ (1/3)*30 = 10 }}} mi
with {{{ 30 - 10 = 20 }}} mi left
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The 3rd day, she hiked {{{ (1/4)*20 = 5 }}} mi
with {{{ 20 - 5 = 15 }}} mi left
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On the 4th day, she hiked 3 mi, so there is
{{{ 15 - 3 = 12 }}} mi left
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The 3 mi on the 4th day was 1/4 of of the
12 mi that is left
OK 
</PRE>