可汗学院
22.g=15-m/32
If Vera starts with a full tank of gas, the number of gallons of gas, , left in the tank after driving mile is given by the equation above. When full, how many gallons of gas does Vera’s tank hold?
A.15 gallons
B.17 gallons
C.30 gallons
D.32 gallons
Correct answer: A Difficulty level: 3
23.Officials project that between 2010 and 2050, the Sub-Saharan African population will drastically change. The model below gives the projection of the population, P, in thousands, with respect to time, t ( provided that 2010 is when t = 0).
p=175+11t/2
What does the 175 mean in the equation?
A.In 2010, the population of Sub-Saharan African was 175 thousand.
B.In 2050, the population of Sub-Saharan African will be 175 thousand.
C.Between 2010 and 2050, the population of Sub-Saharan African will increase by 175 thousand.
D.Between 2010 and 2050, the population of Sub-Saharan African will decrease by 175 thousand.
Correct answer: A Difficulty level: 3
24.S-537.5-1.25p
An artist is carving chess pieces from a large piece of marble. After carving chess pieces, there are pounds of uncarved marble left. As the number of chess pieces carved increases, what happens to the weight of the uncarved marble?
A.There are 125 pounds left.
B.There are 537.5 pounds left.
C.The weight decreases.
D.The weight increases.
Correct answer: C Difficulty level: 3
25.W=-1m/2+16
Henry’s water bottle is leaking at a constant rate. The amount of water, , in ounces, that is left in the water bottle after leaking for minutes is given by the equation above. What does the mean in the equation?
A.The water bottle loses 2 ounces of water per minute.
B.The water bottle loses 1/2 an ounces of water per minute.
C.The water bottle has 1/2 an ounces of water in it at the start.
D.1/2 of the water has leaked from the water bottle in one minte.
Correct answer: B Difficulty level: 3