SAT官方每日一题数学习题及答案解析

　　SAT官方每日一题数学习题 含答案解析

　　2011年2月21日

　　考试类型:Mathematics > Standard Multiple Choice

　　Read the following SAT test question and then click on a button to select your answer.

　　If the graph of the function is a line with slope , which of the following could be the equation of ?

　　A.

　　B.

　　C.

　　D.

　　E.

　　2011年2月18日

　　考试类型:Mathematics > Standard Multiple Choice

　　Read the following SAT test question and then click on a button to select your answer.

　　For how many positive two-digit integers is the ones digit greater than twice the tens digit?

　　A.

　　B.

　　C.

　　D.

　　E.

　　2011年2月15日

　　考试类型:Mathematics > Standard Multiple Choice

　　Read the following SAT test question and then click on a button to select your answer.

　　There are students in a biology class, and only of them are seniors. If juniors are added to the class, how many students in the class will not be seniors?

　　A.

　　B.

　　C.

　　D.

　　E.

　　正确答案:B

　　解析:

　　The graphs of all the given functions are lines, and the equations are all in the form . When a linear equation is in the form , the slope of the graph of the equation is , the coefficient of . The graph of the function is a line with slope , so the only choice that could be the equation of is .

　　正确答案:A

　　解析:

　　The correct answer is (A. If the tens digit is , there are positive two-digit integers with the ones digit greater than twice the tens digit: and . If the tens digit is , there are positive two-digit integers with the ones digit greater than twice the tens digit: and . If the tens digit is , there are positive two-digit integers with the ones digit greater than twice the tens digit: and . If the tens digit is , there is positive two-digit integer with the ones digit greater than twice the tens digit: . If the tens digit is equal to or greater than , then the ones

　　正确答案:D

　　解析:

　　At first, there are students in the class, and of them are seniors. It follows that initially students are not seniors. If juniors are added to the class, there will be , or , students in the class who are not seniors.