Official (CollegeBoard) SAT Math 1 Samples Q9内角 补角 顶角

Fifteen Sample Tests

The Official (CollegeBoard) SAT Math 1 Samples 

Q9 内角 补角 顶角 

Q1. How many of the first 200 positive integers are multiples of neither 6 or 15?

200 /6 =  33,  (1)(6), (2)(6)..... (33) (6).   200 /15 = 13, (1)(15), (2)(6)..... (13) (15). 
里面有重复的。 即30的倍数。 减去多余的.
An integer is a multiple of 6 and 15 if and only if it is a multiple of 30,  6 of them, 30, 60, 90, 120, 150, 180.  Therefore, 200 - ( 33 + 13 - 6) = 160. 
没有为什么要算30倍数解释

Q2. 我怎么没有想 Arithematic sequence 是线性 linear equation.

Q4:

Q5:

Q6:

Q7:

Q8:

Q9:  内角   补角   顶角

Q10:  

Q13:  Drawing a triangle inside a circle, using hypotenuse as a diameter, the height as a radius is a very clever solution.

Q14:  Don't confuse with Sin2A + cos2A = 1, it is for the same angle.

Since B = 90, thus, Sin A = Cos C = a/c

Q15:

Practice 1:

Q4: I can't believe I make a mistake on Q4

Q5: I calculate as a0 + b0 = 100,  x should be x = 180 - 100 = 800. 太粗心，不仔细看题。