Math Jeopardy for Grade 8

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10

What is an arithmetic sequence?

• A sequence of numbers with a common ratio
• A sequence of numbers with a common sum
• A sequence of numbers with a common product
• A sequence of numbers with a common difference

• A sequence of numbers with a common difference

   

10

• What is the common difference in the arithmetic sequence 7, 12, 17, 22, 27?

5 

10

• The first term of an arithmetic sequence is 3, and the common difference is -2. What is the fifth term?

-5

10

• What is the 10th term of the arithmetic sequence with a common difference of 4 and a first term of -2?

• 34

10

• Which term of the arithmetic sequence 3, 8, 13, 18, … is equal to 43?

• 9

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10

• What is the sum of the first 10 terms of the arithmetic series 3, 7, 11, 15, …?

210

10

Which of the following is NOT an arithmetic sequence?

• 2, 5, 8, 11, 14, …   
• 1, 2, 4, 8, 16, …
• 10, 7, 4, 1, -2, …    
• 0, 3, 6, 9, 12, ….

• 1, 2, 4, 8, 16, …

10

• If the 8th term of an arithmetic sequence is 31 and the common difference is 3, what is the formula for the nth term?

• a_n = 3n + 7

10

• How many terms are in the sequence 8, 11, 14, …, 50?

• 16

10

Find the value of x such that x + 2, 4x + 1, and 6x + 3 are consecutive terms in an arithmetic sequence.

• x =1               
• x = 3
• x = 2                       
• x = 4

• x = 3

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10

• Simplify the ratio 18:42 to its simplest form.

3:7      

10

Which of the following equations represents a direct proportion between variables y and x, where k is the constant of proportionality?

• y = kx²                  
• y = kx
• x + y = k               
• y = k/x

 

• y = kx

10

• If y is directly proportional to x, and y = 15 when x = 3, what is the constant of proportionality, k?

• 5

10

• A graph of a direct proportion (y=kx) is a straight line. Through which point must this line always pass?

(0,0)

10

The time (T) it takes to paint a house is inversely proportional to the number of painters (N). Which equation represents this relationship, where k is the constant of proportionality?

• T = N + k              
• T = k square root of N
• T = Kn                  
• T = k/N

• T = k/N

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10

• If y is inversely proportional to x, and y = 4 when x = 8, what is the constant of proportionality, k?

32

10

• If y is directly proportional to x, and y = 20 when x = 5, find y when x = 9.

36

10

• What is the shape of the graph that represents an inverse proportion, y = k/x (for k > 0)?

A hyperbola

10

• A chef wants to divide 30 kg of rice into two bags in the ratio 2:3. How much rice will be in the larger bag?

• 18 kg

10

Which of the following scenarios represents an inverse proportion?

• The price of gasoline and the amount of gas you can buy with $20.
• The age of a person and their height.
• The circumference of a circle and its diameter.
• The number of hours worked and the money earned at a fixed hourly rate.

• The price of gasoline and the amount of gas you can buy with $20.

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10

• The relationship between two variables, x and y, is given by the table of values: (2, 10), (4, 5), (10, 2). What type of relationship is this?

• Inverse proportion

10

• A team of 5 workers can complete a project in 10 days. If the work is inversely proportional to the number of workers, how long would it take 2 workers to complete the same project?

25 days

10

For the graph of an inverse proportion, y = k/x (with k>0), what happens to the value of y as the value of x approaches infinity?

• y approaches infinity.
• y approaches the value of k.
• y approaches zero.
• y approaches a negative number.

      

• y approaches zero.

10

Which of the following equations represents exponential decay?

• y = 5 (0.80)^x        
• y = 0.5 (2)^X
• y = 3 (1.5)^x           
• y = 2x + 7

y = 5 (0.80)^x

10

Which of the following equations represents exponential growth?

• y = 5x²                 
• y = 10(1/4)^x
• y = 0.5(3)^x          
• y = 100(0.99)^x

y = 0.5(3)^x 

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10

A population of bacteria starts at 100 and grows by 5% every hour. Which equation models this growth?

• P(t) = 100(1.05)^t
• P(t) = 100(0.5)^t
• P(t) =  100(5)^t  
• P(t) = 100 + 1.05t

• P(t) = 100(1.05)^t

10

• What is the equation of the horizontal asymptote for the basic exponential function y = 3^x?

• y = 0

10

What is the domain of the function y = 2^x?

• All non-negative real numbers 
• All positive real numbers 
• Only integers
• All real numbers

• All real numbers

10

Which of the following functions exhibits the fastest exponential growth?

• y = 5(2)^x             
• y = 4^x
• y =  3(1.5)^x                   
• y = 10(3)^x

• y = 4^x

10

• An exponential function has a growth factor of 1.15. What is the percentage growth rate?

• 15%