Geometric Sequences Trivia Questions Quiz

1) Determine which sequence is geometric.

-16, -13, -10, -7, ...

1, 1, 2, 3, 5, ...

-3, -6, -12, -24, ...

5, 7, 9, 11, ...

The sequence -3, -6, -12, -24, ... is geometric because each term is obtained by multiplying the previous term by a constant factor of -2.

Explanation

The sequence -3, -6, -12, -24, ... is geometric because each term is obtained by multiplying the previous term by a constant factor of -2.

2) What is the 7th term of the geometric sequence:

3 over 64 comma space fraction numerator minus 3 over denominator 16 end fraction comma space 3 over 4 comma space minus 3 comma space...

-48

192

3072

-12288

The given sequence is a geometric sequence where each term is obtained by multiplying the previous term by a constant factor. In this case, the common ratio is -4. To find the 7th term, we can use the formula for the nth term of a geometric sequence: an = a1 * r^(n-1). Plugging in the values, we get a7 = -48 * (-4)^(7-1) = -48 * (-4)^6 = -48 * 4096 = -196,608. However, this answer does not match any of the given options. Therefore, the correct answer is not available or there may be an error in the question.

Explanation

The given sequence is a geometric sequence where each term is obtained by multiplying the previous term by a constant factor. In this case, the common ratio is -4. To find the 7th term, we can use the formula for the nth term of a geometric sequence: an = a1 * r^(n-1). Plugging in the values, we get a7 = -48 * (-4)^(7-1) = -48 * (-4)^6 = -48 * 4096 = -196,608. However, this answer does not match any of the given options. Therefore, the correct answer is not available or there may be an error in the question.

3) Find the next two terms of the geometric sequence 50, 40, 32, ...

24, 15768

25.6, 20.48

26, 22128

28.5, 25.52

The given geometric sequence is obtained by multiplying each term by 0.8. To find the next term, we multiply the last term (32) by 0.8, resulting in 25.6. To find the term after that, we again multiply by 0.8, giving us 20.48. Therefore, the next two terms of the geometric sequence are 25.6 and 20.48.

Explanation

The given geometric sequence is obtained by multiplying each term by 0.8. To find the next term, we multiply the last term (32) by 0.8, resulting in 25.6. To find the term after that, we again multiply by 0.8, giving us 20.48. Therefore, the next two terms of the geometric sequence are 25.6 and 20.48.

4) The 15th term of a geometric sequence is 32,768. Which choice shows the possible first term and the possible common ratio?

2, 2

4, 3

15, 4

8, -4

In a geometric sequence, each term is found by multiplying the previous term by a constant value called the common ratio. To find the 15th term, we start with the first term and multiply it by the common ratio 14 times. Given that the 15th term is 32,768, it means that the first term multiplied by the common ratio 14 times equals 32,768. The only choice that satisfies this condition is 2 as the first term and 2 as the common ratio.

Explanation

In a geometric sequence, each term is found by multiplying the previous term by a constant value called the common ratio. To find the 15th term, we start with the first term and multiply it by the common ratio 14 times. Given that the 15th term is 32,768, it means that the first term multiplied by the common ratio 14 times equals 32,768. The only choice that satisfies this condition is 2 as the first term and 2 as the common ratio.

5) Find the fifth term in a sequence in which the first term is 3 and the common ratio is -4.

60

-3072

-729

768

The given sequence is a geometric sequence with a first term of 3 and a common ratio of -4. To find the fifth term, we can use the formula for the nth term of a geometric sequence: an = a1 * r^(n-1). Plugging in the values, we get a5 = 3 * (-4)^(5-1) = 3 * (-4)^4 = 3 * 256 = 768. Therefore, the fifth term in the sequence is 768.

Explanation

The given sequence is a geometric sequence with a first term of 3 and a common ratio of -4. To find the fifth term, we can use the formula for the nth term of a geometric sequence: an = a1 * r^(n-1). Plugging in the values, we get a5 = 3 * (-4)^(5-1) = 3 * (-4)^4 = 3 * 256 = 768. Therefore, the fifth term in the sequence is 768.