问题
单项选择题
An instructor scored a student’s test of 50 questions by subtracting 2 times the number of incorrect answers from the number of correct answers. If the student answered all of the questions and received a score of 38, how many questions did that student answer correctly ？（）
A．19
B．38
C．41
D．44
E．46
答案
参考答案：E
解析：
设该学生答对的题数为x，根据题意可得：
x-2(50-x)=38
x=46