Verbal Reasoning - Series Completion - Discussion
Discussion Forum : Series Completion - Section 1 (Q.No. 4)
Directions to Solve
Choose the correct alternative that will continue the same pattern and replace the question mark in the given series.
4.
In the series 2, 6, 18, 54, ...... what will be the 8th term ?
Answer: Option
Explanation:
Clearly, 2 x 3 = 6, 6 x 3 = 18, 18 x 3 = 54,.....
So, the series is a G.P. in which a = 2, r = 3.
Therefore 8th term = ar8-1 = ar7 = 2 x 37 = (2 x 2187) = 4374.
Discussion:
27 comments Page 1 of 3.
Madalin said:
4 years ago
2 + 2 = 4 + 2 = 6,
6 + 6 = 12 + 6 = 18,
18 + 18 = 36 + 18 = 54,
54 + 54 = 108 + 54 = 162,
162 + 162 = 324 + 162 = 486,
486 + 486 = 972 + 486 = 1458,
1458 + 1458 = 2916 + 1458 = 4374.
2, 6, 18, 54, 162, 486, 1458, 4374. 8th term is 4374.
6 + 6 = 12 + 6 = 18,
18 + 18 = 36 + 18 = 54,
54 + 54 = 108 + 54 = 162,
162 + 162 = 324 + 162 = 486,
486 + 486 = 972 + 486 = 1458,
1458 + 1458 = 2916 + 1458 = 4374.
2, 6, 18, 54, 162, 486, 1458, 4374. 8th term is 4374.
(15)
Nabin bahadur shahi said:
4 years ago
Good method, thanks @Kanna.
(3)
James Antony said:
4 years ago
Thanks @Kanna.
(2)
Aswini said:
1 decade ago
What does GP mean?can anyone explain me please.
(1)
Amrit hayer said:
9 years ago
The sum of first 3 terms of G.P is 16 and the sum of next 3 terms is 128. Find 1st term, common ratio and sum 20 terms? please solve this.
(1)
Nigerian boy said:
10 years ago
@Sameer.
From the formula T8 = ar (power N-1).
N stands for Number of terms you are looking for so all you need do is know that you have to subtract 1 from the number of terms.
Eg. 1. When the number of terms in question is 9 then the formula becomes T9 = ar9-1.
2. When it is 5 the formula becomes T5 = ar5-1.
From the formula T8 = ar (power N-1).
N stands for Number of terms you are looking for so all you need do is know that you have to subtract 1 from the number of terms.
Eg. 1. When the number of terms in question is 9 then the formula becomes T9 = ar9-1.
2. When it is 5 the formula becomes T5 = ar5-1.
(1)
Sameer said:
10 years ago
Why ^7 instead ^8 because there find out 8th place?
(1)
Kanhay said:
1 decade ago
A means first term and are means common ratio.
(1)
Chiran said:
1 decade ago
What is the meaning of a and r please explain me?
Nida said:
6 days ago
Thanks all for explaining it.
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