Question 1171916
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If B is the number of big cakes, then the number of small cakes is (12-B).


You then write the total money equation


    1.75*(12-B) + 3.85*B = 31.50   dollars.


From the equation


    B = {{{(31.50-1.75*12)/(3.85-1.75)}}} = 5.


<U>ANSWER</U>.  5 big cakes and 12-5 = 7 small cakes.
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Solved.