12.Practice.Tests.for.the.SAT_2015-2016_1128p

KAPLAN'S GUIDE TO THE SAT CHANGE AND PRACTICE QUESTIONS 41
3. A
Choice (A) is correct. Between x = 2 and x = 3, the
slope of the graph representing the temperature of
Object 1 (the dashed line) is steeper than the slope of
the graph representing Object 2 (the solid line). This
means the temperature of Object 1, not Object 2,
decreased at a faster rate between 2 and 3 hours, so
this statement does not accurately describe the data.
4. A
Choice (A) is correct. Because the airplane is traveling
at an average speed of 500 miles per hour and
the plane's fuel mileage is 0.2 miles per gallon, the
number of gallons of fuel used each hour can be
500 miles 1 gallon 500
f oun d b y x - ga 11 ons per
1 hour 0.2 miles 0.2
hour. This means that in t hours, the plane uses
500 500t
-xt, or -- , gallons of fuel. The plane's tank
0.2 0.2
has 42,000 gallons of fuel at the beginning of the
flight, so after t hours the amount of fuel remaining
. 500t
IS f(t) = 42,000 - -
·
0.2
S. B
Choice (B) is correct. To answer this question, students
must select the relevant information from
the table and compute the percentage for each
age group. The relevant information consists of the
number of people in the age group that reported
owning a Smart Phone (first column of numbers)
and the total number of people that were surveyed
in that age group (last column of numbers). The
calculations are as follows:
28,542
15- to 29-year-olds: ""48.5%
58,881
33,1 16
30- to 44-year-olds· . ""49.5% (t h e h' 1g h est)
66,838
6. c
Choice (C) is correct. To answer this question,
extrapolate from a random sample to estimate the
number of 15- to 29-year-olds who watch streaming
videos on their Smart Phones. This is done by
multiplying the fraction of people in the follow-up
survey that responded Yes by the total population of
15- to 29-year-olds that own a Smart Phone which
. Id
302
y1e s - x28,542 =17,239 .
500
7A. 2.25
The charge amount of $126.48 represents the conversion
of 128 + 66 + 85 = 279 Brazilian reais plus the
2% fee that Eli's credit card company charged him.
To find the original cost, c, of the vases in U.S. dollars
(before the 2% fee), write and solve the equation,
1.02c = 126.48. Dividing both sides of the equation
by 1.02 results in a cost of c = $124.
To find the foreign exchange rate, r, in Brazilian reais
per U.S. dollar, students let units guide you:
r reais . 279
124 dollars x -- = 279 rea1s -+ r = - = 2.25
1 dollar 124
The exchange rate on Monday was 2.25 Brazilian
reais per U.S. dollar.
78. 3 or .03
Break this problem into parts, solving one piece at
a time. Find the original converted price, use the
result to calculate the exchange rate for Wednesday,
and then use the two exchange rates from Monday
and Wednesday to find the net change in the rates
as a percentage.
If p represents the original price in U.S. dollars, then
the total charge of $358.50 represents 1.02(200) +
1.03(p - 200). Setting the total charge equal to this
expression and solving for p yields:
11,960
45- to 59-year-olds: ""30.0%
39,914
1,023
60- year-olds and over: -- .. 27.0%
3,782