we have that
Cheryl  mixes
7 pints of Apple juice
and 
7 pints of cranberry juice
we know that
total mixed fruit drink-----> 7+7-----> 14 pints
1 pint-------> is equals to 16 fluid ounces
then
14 pints----------> X
X=14*16-----> x=224 fluid ounces
the answer is 
224 fluid ounces