可汗
8.Dalia is installing a tile floor in a rectangular room. Dalia has 152 tiles available to tile the room. If each row requires 9(1/2)?? tiles, and 19 tiles break while Dalia is laying the floor, how many full rows of tile can she install before running out of tiles?
A.12
B.14
C.16
D.18
correct answer: B difficult degree: 2
9.Phytoremediation is the use of plant growth to purify pollutants from soil, water, or air. Suppose that a crop of brake ferns can remove 15 milligrams (mg) per square meter of a particular pollutant from the soil in 20 weeks. After 20 weeks, the ferns are harvested and a new crop is planted. If cc represents the number of crops of brake ferns needed to phytoremediate soil contaminated with 170mg per square meter of the pollutant down to healthy levels of 5mg per square meter, which equation best models the situation?
A.170-20c=5
B.170+20c=5
C.170-15c=5
D.170+20c=5
correct answer: C difficult degree: 2
11.Cara is hanging a poster that is 91 centimeters (cm) wide in her room. The center of the wall is 180cm from the right end of the wall. If Cara hangs the poster so that the center of the poster is located at the center of the wall, how far will the left and right edges of the poster be from the right end of the wall?
A.225.5cm and 89cm, respectively
B.271.5cm and 134.5cm, respectively
C.225.5cm and 134.5cm, respectively
D.271cm and 89cm, respectively
correct answer: C difficult degree: 2
12.Felipe is saving money for a class trip. He already has saved $250 that he will put toward the trip. To save more money for the trip, Felipe gets a job where each month he can add $350 to his savings for the trip. Let m be the number of months that Felipe has worked at his new job. If Felipe needs to save $2700 to go on the trip, which equation best models the situation?
A.250m?350=2700
B.250m+350=2700
C.350m?250=2700
D.350m+250=2700
correct answer: D difficult degree: 2
13.Camille and Hiroki have decided to start walking for exercise. Camille is going to walk 7 miles the first day and 3 miles each day after that. Hiroki is too busy to walk on the first 2 days, so he decides to walk 5 miles each day until he has walked the same number of miles as Camille. If Camille and Hiroki will have walked the same number of miles, how many days will Camille have walked?
A.2
B.3
C.5
D.7
correct answer: D difficult degree: 2
15.At the county fair, the operator of a game guesses a contestant’s weight. For each pound the operator’s guess differs from the contestant’s weight, the contestant will receive $3. If a contestant received $15 when the operator guessed 120
15.ounds, what are the possible values for the weight of the contestant?
A.105 and 115
B.105 and 125
C.115 and 125
D.115 and 135
correct answer: C difficult degree: 2
