Princeton Review
Each of the even-numbered terms in a certain sequence is formed by multiplying the preceding term by –1. Each of the odd-numbered terms in the sequence is formed by adding 3 to the preceding term. If the first term in the sequence is 3, then what is the 168th term?
A. -3
B. -1
C. 0
D. 1
E. 3
OA C
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Each of the even-numbered terms in a certain sequenceis formed by multiplying the preceding term...
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deloitte247
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- Even terms are formed by multiplying the preceding term by - 1
- Odd terms are formed by adding 3 to the preceding term by 3
- First term = 3
1st term = 3
2nd term = 3 * (-1) = -3
3rd term = -3 + 3 = 0
4th term = 0 * -1 = 0
5th term = 0 + 3 = 3
6th term = 3 * - 1 = -3
7th term = - 3 + 3 = 0
8th term = 0 * -1 = 0
Every third and fourth term in the series yields 0
Since 168/4 = 42 168th term will be one of the fifth term and will be 0
Answer = C
- Odd terms are formed by adding 3 to the preceding term by 3
- First term = 3
1st term = 3
2nd term = 3 * (-1) = -3
3rd term = -3 + 3 = 0
4th term = 0 * -1 = 0
5th term = 0 + 3 = 3
6th term = 3 * - 1 = -3
7th term = - 3 + 3 = 0
8th term = 0 * -1 = 0
Every third and fourth term in the series yields 0
Since 168/4 = 42 168th term will be one of the fifth term and will be 0
Answer = C
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Scott@TargetTestPrep
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Solution:AAPL wrote: ↑Tue Nov 24, 2020 5:28 pmPrinceton Review
Each of the even-numbered terms in a certain sequence is formed by multiplying the preceding term by –1. Each of the odd-numbered terms in the sequence is formed by adding 3 to the preceding term. If the first term in the sequence is 3, then what is the 168th term?
A. -3
B. -1
C. 0
D. 1
E. 3
OA C
Let a_n be the nth term. We see that:
a_1 = 3
a_2 = -3
a_3 = 0
a_4 = 0
a_5 = 3,
a_6 = -3
a_7 = 0
a_8 = 0
We see that the terms repeat in a four-number pattern: 3, -3, 0, 0. Note that the 4th, 8th, and 12th terms are equal to 0, and any term number that is a multiple of 4 is also equal to 0. Since 168 is a multiple of 4, the 168th term is also equal to 0..
Answer: C
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