Which coordinate is not on the line y = 3x – 1?
A) (0, -1)
B) (-1, 2) (Correct Answer)
C) (2, 5)
D) (4, 11)
Explanation:
To determine which coordinate does not represent the line y = 3x – 1, replace the variables x and y with the ordered pair values. In this case, replacing the variable x with the value of -1 yield -4, not 2.
Related Common Core State Standard: Functions: 8.F.1
Which of the four functions has the largest rate of change?
A) Function 1 (Correct Answer)
B) Function 2
C) Function 3
D) Function 4
Explanation:
The rate of change for function 4 is 3.5, for function 3 is 3, for function 2 is 2, and for function 1 is 4. Therefore, function 1 has the largest rate of change.
Related Common Core State Standard: Functions: 8.F.2
Change the rational repeating decimal number 0.5555… to a fraction.
A) 1/5
B) 1/2
C) 5/9 (Correct Answer)
D) 5/11
Explanation:
First, assume x = 0.5555…
Then, multiply both sides by 10. 10x = 5.555…
Next, subtract the first equation x = 0.5555… from the second equation 10x = 5.555…
10x = 5.5555…
– x = 0.5555…
9x = 5
Finally, solve for x. 9x = 5; x = 5/9
Related Common Core State Standard: The Number System: 8.NS.1
Jason and Maggie are playing a board game that uses 2 different types of spinners. It is Jason’s turn and he needs to spin a B on one spinner and a 4 on the other spinner to win the game on this turn. What are his chances of winning the game on this turn?
A) 50%
B) 3% (Correct Answer)
C) 13%
D) 25%
Explanation:
The probability of spinning a “B” on the first spinner is “1 out of 4” or 0.25. The probability of spinning a “4” on the second spinner is “1 out of 8” or 0.125. The probability of both of these events happening is the product of their respective probabilities. The probability would be 0.25 * 0.125 = 0.03125 (or about 3%).
Related Common Core State Standard: Statistics and Probability: 8.SP.4
Andy’s job is to attach a ladder to a water tank. The water tank
is a 20ft wide cylinder and has a volume of 9,420ft3. If the length
of the ladder is equal to the height of the water tank, how long
is the ladder?
A) 30ft (Correct Answer)
B) 9.5ft
C) 8.9ft
D) 11ft
Explanation:
The water tank is a cylinder with a volume of 9,420ft3. Therefore 9,420 = (?) (r2) (h) = (3.14) (102) (h) = (3.14) (100) h;
h ? 30ft
Related Common Core State Standard: Geometry: 8.G.9
Al fills an ice cream cone to the top edge. The diameter of the ice
cream cone is 2 inches and its height is 6 inches. Don fills a bowl
(V = 5 cubic inches) with ice cream. Al has how much more ice
cream than Don?
A) 1.2in3
B) 1.28in3 (Correct Answer)
C) 1.1in3
D) 1in3
Explanation:
The ice cream cone has a diameter of 2 inches and a height of 6 inches.
Therefore the volume of the cone V = (1/3) (?) (r2) (h) = (1/3) (3.14) (1) (6) = 18.84/3 = 6.28in3
The difference in volume is 6.28 – 5 = 1.28in3
Related Common Core State Standard: Geometry: 8.G.9
Juan has forty dollars in his jacket. Every day he spends half of the
money that is in the jacket. On the first day (Monday), he spends
$20 leaving him with twenty dollars. On what day will he start with
less than $3.00 in his jacket?
A) Friday (Correct Answer)
B) Thursday
C) Tuesday
D) Saturday
Explanation:
On Monday, Juan starts the day with 40 dollars. He ends the day with half that amount ($20).
He starts Tuesday with 20 dollars and ends with $10. He starts Wednesday with 10 dollars
and ends the day with $5. He starts Thursday with 5 dollars and ends the day with $2.50.
He starts Friday with $2.50. Friday is the first day that Juan starts with less than $3.
Related Common Core State Standard: Functions: 8.F.4
The bowling team’s scores at last week’s competition were 123, 140,
155, 143, and 167. What is the median score for the team?
A) 44
B) 155
C) 123
D) 143 (Correct Answer)
Explanation:
To find the median of a set of numbers, the numbers should first be listed in increasing order.
This set would be 123, 140, 143, 155, 167. The median is the number in the middle of the set.
In this case it is the third number, 143.
Related Common Core State Standard: Statistics and Probability 8.SP.1
Jacci has a fair coin and a wooden cube. On the cube, there are two
faces colored green, two faces colored blue, and two faces colored
red. Mary flips the coin and tosses the cube. What is the probability
of getting both a tail on the toss of the coin and a green face on the
roll of the cube?
A) 1/4
B) 1/6 (Correct Answer)
C) 1/12
D) 1/2
Explanation:
The probability of flipping a tail on a fair coin is ½. The probability of rolling “Green” on the
wooden cube described in the problem would be 2/6, or 1/3. The probability of both events
occurring is the product of their respective probabilities. The product of ½ and 1/3 is 1/6.
Jacci has a 1/6 chance of flipping a tail and rolling a “Green.”
Related Common Core State Standard: Statistics and Probability: 8.SP.4
Point J has the coordinates (-5, 6). What are the coordinates of its
image if it is reflected in the y-axis?
A) (5, -6)
B) (5, 6) (Correct Answer)
C) (-5, 6)
D) (-6, 5)
Explanation:
When a point is reflected over the y-axis, the x-coordinate switches to its opposite. The y-coordinate does not change. Therefore, the image of (-5, 6) would be (5, 6).
Related Common Core State Standard: Geometry 8.G.3
What is the tenth number in the pattern below?
1, 3, 4, 12, 13, 39, 40
A) 360
B) 363 (Correct Answer)
C) 123
D) 121
Explanation:
The rule for this pattern could be described: “Multiply by 3. Add 1.” Continuing the pattern using this rule, the 8th term would be 120 (40 * 3), the 9th term would be 121 (120+1), and the 10th term would be 363 (121 * 3).
Related Common Core State Standard: Statistics and Probability 8.SP.1
What is the volume of a cone with the height of 6 inches and the
diameter of 4 inches?
A) 25.20in3
B) 25.12in3 (Correct Answer)
C) 26in3
D) 25in3
Explanation:
The equation for the volume of a cone is V = ? x r2 x h / 3. ‘r’ is determined
by D/2, which is: 4cm / 2 = 2cm, insert the value of ‘r’ we have:
V = 3.14 x 22 x 6 / 3
V = 75.36 / 3 = 25.12 cubic inches
Related Common Core State Standard: Geometry 8.G.9
Solve for x in the following equation
– 46 = 8 – 2x
A) 18
B) -27
C) 27 (Correct Answer)
D) -18
Explanation:
The following steps could be followed to solve this equation:
-46 = 8 – 2x (+2x)-46 = 8 – 2x (+2x) (Add 2x to both sides.)
2x – 46 = 8 (Simplify.)
2x – 46 (+46) = 8 (+46) (Add 46 to both sides.)
2x = 54 (Simplify & Divide both sides by 2.)
x = 27 (Simplify.)
Related Common Core State Standard: 8.EE.7
Three adults take 15 students to an art exhibit. The total amount
spent on tickets is $75. Adult tickets are $10 apiece. How much
does each student ticket cost?
A) $2.00
B) $3.00 (Correct Answer)
C) $4.00
D) $5.00
Explanation:
Three adults bought tickets. Each adult ticket costs $10. That means $30 was spent on adult tickets.
That leaves $45 ($75 – $30) that was spent on 15 student tickets. $45 divided by 15, yields a cost of
$3.00 per student ticket.
Related Common Core State Standard: 8.EE.5
Mr. Smith is 81 years older than his grandson, Victor. In 3 years,
Mr. Smith will be four times as old as Victor. How old is Victor now?
A) 21 years old
B) 22 years old
C) 24 years old (Correct Answer)
D) 27 years old
Explanation:
Let v represent Victor’s age. Then Mr. Smith’s age would be represented by (v + 81.) Three years from now, Victor’s age will be (v + 3), and Mr. Smith’s age will be (v + 84). According to the problem, Mr. Smith’s age 3 years from now (v + 84) will be equal to 4 times Victor’s age 3 years from now (v + 3). As an equation this would be written: v + 84 = 4(v + 3). Solving for v yields the solution v = 24. Victor is now 24 years old.
Related Common Core State Standard: 8.EE.C.7
Click Here to Watch Educational videos on 8th Grade Expressions and Equations
Kelsey got a 74% on her Social Studies test. The test had 50 questions.
How many questions did she NOT answer correctly?
A) 12
B) 50
C) 13 (Correct Answer)
D) 37
Explanation:
If Kelsey scored 74% on a 50-question test, then she answered 37 of the questions correctly.
(0.74 · 50 = 37.) This means she answered the remaining 13 questions incorrectly.
Related Common Core State Standard: 8.EE.7
In New Jersey, an average of 62% of a person’s property taxes goes
to support schools. If a person’s property taxes are $7,200 a year,
then how much money will go to schools?
A) $7,200
B) $4,464 (Correct Answer)
C) $460,800
D) $4,400
Explanation:
To find 62% of $7,200, it would be necessary to calculate 7,200 * 0.62. The product is 4,464.
An average of $4,464 of each person’s property taxes goes to the schools.
Related Common Core State Standard: 8.EE.7
Josephine took her sister out to dinner. When the bill came, her sister
reminded her that it is customary to tip the server 15% of the bill for
satisfactory service. What is the tip if the bill is $24?
A) $1.88
B) $2.30
D) $5
Explanation:
10% of $24.00 is $2.40. 20% of $24.00 is $4.80.
15% of $24.00 would be between $2.40 and $4.80. The answer is $3.60
Related Common Core State Standard: 8.SP.1
If x squared equals 47 then what is the approximate value of x?
A) 49
B) 6
C) 5
D) 7 (Correct Answer)
Explanation:
The number 47 is close to the perfect square 49. Therefore, the square root of 47 is slightly
less than 7, the square root of 49. The value of x is approximately 7.
Related Common Core State Standard: 8.EE.2
Suppose three days ago was Tuesday. What day of the week will it be 90 days from today?
A) Monday
B) Thursday (Correct Answer)
C) Friday
D) Saturday
Explanation:
If, according to the problem, it was Tuesday three days ago, then today must be Friday. The days of the week repeat in sets of 7. If today is Friday, then 91 days from now will be Friday as well, since 91 is a multiple of 7. Thus, 90 days from now will be the day before Friday, or Thursday.
Related Common Core State Standard: 8.EE.7
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