A teacher graded 10 students. If the teacher added X points to the score of each student on the basis of the original one, or reduced Y points to that of each student. What was the difference between the average scores in the two cases?
1：X+Y=20
2：X-Y =4
-
AStatement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
-
BStatement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
-
CBoth statements TOGETHER are sufficient, but NEITHER one ALONE is sufficient.
-
DEACH statement ALONE is sufficient.
-
EStatements (1) and (2) TOGETHER are NOT sufficient.
显示答案
正确答案: A