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 2 of 3.
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.
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.
Vaishnavi said:
9 years ago
Yes, using formula is also the correct method.
Nrusingha acharya said:
10 years ago
An other method: 2.
6*3^0.
6*3^1.
6*3^2.
6*3^3.
6*3^4.
6*3^5.
6*3^6,
Only calculate the 8th one not all and get the result.
6*3^0.
6*3^1.
6*3^2.
6*3^3.
6*3^4.
6*3^5.
6*3^6,
Only calculate the 8th one not all and get the result.
Upender Singh Rajput said:
1 decade ago
Solving with GP. (Geometrical Progression) find 8th term.
Now Series is 2 6 18 54.....8th term.
So a =2, r=6\2=3, T8=2(3)7, T8 = 4374.
Now Series is 2 6 18 54.....8th term.
So a =2, r=6\2=3, T8=2(3)7, T8 = 4374.
Prem said:
1 decade ago
We have to go with formula only ?
Sangeeta said:
1 decade ago
This series is in geometric progression:
So 8th term is = 2*3^(8-1).
= 2*3^(7).
= 2*3^(4+3).
= 2*[3^4*3^3].
= 2*[81*27].
= 2*2187.
= 4374.
So 8th term is = 2*3^(8-1).
= 2*3^(7).
= 2*3^(4+3).
= 2*[3^4*3^3].
= 2*[81*27].
= 2*2187.
= 4374.
Manjot singh said:
1 decade ago
2*3 = 6.
6*3 = 18.
18*3 = 54.
54*3 = 162.
162*3 = 486.
486*3 = 1458.
1458*3 = 4374.
6*3 = 18.
18*3 = 54.
54*3 = 162.
162*3 = 486.
486*3 = 1458.
1458*3 = 4374.
Sameer said:
1 decade ago
@Kanna.
Why we need to multiply with 3 With Given Numbers?
Why we need to multiply with 3 With Given Numbers?
Biji said:
1 decade ago
A = 2.
R = 3.
N = 8 th term.
= 2*3^(8-1).
= 2*3^7.
= 2(3^7) = 2(3^2 * 3^2 * 3^2 * 3).
= 2(9*9*9*3) = 2(81*27).
= 2(2187) = 4374.
3^7 = 3 square * 3 Square * 3 Square * 3.
R = 3.
N = 8 th term.
= 2*3^(8-1).
= 2*3^7.
= 2(3^7) = 2(3^2 * 3^2 * 3^2 * 3).
= 2(9*9*9*3) = 2(81*27).
= 2(2187) = 4374.
3^7 = 3 square * 3 Square * 3 Square * 3.
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