The following data sufficiency problems consist of a question and two statements, labeled (1) and (2), in which certain data are given. You have to decide whether the data given in the statements are sufficient for answering the question. Using the data given in the statements plus your knowledge of mathematics and everyday facts (such as the number of days in July or the meaning of counterclockwise), you must indicate whether.
Any decimal that has a finite number of nonzero digits is a terminating decimal. For example, 16, 12.43, and 0.26 are all terminating decimals. If a and b are positive integers and the ratio a/b is expressed as a decimal, is a/b a terminating decimal ？（）
(1) b=5
(2) 70＜a＜80
A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
参考答案：A
解析：
alone is sufficient because any positive integer divided by 5 will have a remainder of either 0, 1, 2, 3, or 4, which translate into terminating decimals of either 0.0, 0.2, 0.4, 0.6, or 0.8; therefore, if b=5, then a/b has to be a terminating decimal. (2) alone is insufficient because it does not give the value for b;, if, for example, b=5, then any of the numbers in that range would result in terminating decimals, but if b=3, then 71/3=23.666666666....