Zachary is helping his younger brother, Sterling, learn his multiplication tables. For every question that Sterling answers correctly, Zachary gives him 3 pieces of candy. For every question that Sterling answers incorrectly, Zachary takes away two pieces of candy. After 7 questions, if Sterling had answered 2 more questions correctly, he would have earned 31 pieces of candy. How many of the 7 questions did Zachary answer correctly? Pick.
A) 6 B) 7 C) 8 D) 9 E) 10
i got two equations:   3x-2y=25   x+y=7   3x-2(7-x)=25   3x-14+2x=25   5x=39   x=7.8 or between 7 and 8. (ANS 7)
<result>B</result>
Zachary is helping his younger brother, Sterling, learn his multiplication tables. For every question that Sterling answers correctly, Zachary gives him 3 pieces of candy. For every question that Sterling answers incorrectly, Zachary takes away two pieces of candy. After 7 questions, if Sterling had answered 2 more questions correctly, he would have earned 31 pieces of candy. How many of the 7 questions did Zachary answer correctly?