Tip #30 to Get a Top SAT Math Score

Example Problems

Note: The following questions are out of Easy, Medium, Hard order because of the length of #3 and available room on the page.

Easy

1. If a movie offends 50 people in a theater just by the title of the movie, and 25 more people with each joke, which of the following equations express the number of people offended after x number of jokes?
   1. y = 50
   2. y = 50x + 25
   3. y = 25x
   4. y = 75x
   5. y = 25x + 50
2. If (2, g) is a solution to the equation y =–2x + 3, then g =

Hard

3. If the equation of line j is y = mx – 2 and line k is perpendicular to line j at the point (2, 1), what is the equation of line k ?

Medium

4. For the equation y = ax + b, Alex knew that b should be 4 and that the slope was positive. Which of the following could be the graph of this line?

Answers

1. E   25 people are offended by each joke, so that number goes next to x. 50 people are offended right off the bat, and this number does not change with the number of outrageous jokes in the movie, so that number goes alone. y = 25x + 50.
2. –1   If you are given a point and an equation, plug in the point and solve for the unknown:

y = –2x + 3

g = –2(2) + 3

g = –1

3. E   If you are give a point and an equation, plug in the point and solve for the unknown. So plug (2,1) into y = mx – 2 to get m = . Since line k is perpendicular to line j, its slope must be Thus, y = x + b. Again, plug in (2,1) to get y =
4. E   Great question; most SATs have one like this. Alex knew that b = 4, so the y intercept is 4, and that a is positive, so the graph rises from left to right. (Review slope in Skill 11 if needed. If you slacked during the slope chapter and did not do the drills, e-mail me and I'll send a motivational speech your way.) Choice B is the only choice that satisfies both requirements of y intercept of 4 and positive slope.

Go to: Tip #31