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 3 of 3.
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)
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)
Papai said:
4 years ago
ar^n-1 where n=no of term, a=first elementary.
So,
2*3^7=4374.
So,
2*3^7=4374.
Nabin bahadur shahi said:
4 years ago
Good method, thanks @Kanna.
(3)
James Antony said:
4 years ago
Thanks @Kanna.
(2)
Chollangi sankar said:
3 months ago
2 * 3 = 6.
3 * 3 = 18.
18 * 3 = 54.
54 * 3 = 162.
162 * 3 = 486.
486 * 3 = 1458.
1458 * 3 = 4374.
3 * 3 = 18.
18 * 3 = 54.
54 * 3 = 162.
162 * 3 = 486.
486 * 3 = 1458.
1458 * 3 = 4374.
Nida said:
6 days ago
Thanks all for explaining it.
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