可汗SAT数学练习：Systems of linear inequalities word problems【2】
7.Prachi needs between 240 and 260 total feet of fence panels. The home improvement store has 24 short (6-foot) fence panels and 28 long (8-foot) fence panels in stock. Which of the following combinations of fence panels could she buy?
A. 6 short fence panels and 26 long fence panels
B. 8 short fence panels and 23 long fence panels
C. 27 short fence panels and 12 long fence panels
D. 30 short fence panels and 10 long fence panels
CORRECT ANSWER: A DIFFICULTY LEVEL: 3
8.Li Qiang is listening to a symphony that has 2 movements. The first movement has 3 beats per measure and the second movement has 4 beats per measure. The symphony has 446 measures. In an attempt to count the beats, Li Qiang counts at least x of the beats in the first movement and exactly b beats in the second movement. Let x be the number of beats in the first movement and b be the number of beats in the second movement. Which of the following inequalities must be true?