Question Detail

In the series 2, 6, 18, 54, ... what will be the 8th term ?

  • 4174
  • 4150
  • 4274
  • 4374

Answer: Option D

Explanation:

We can see the given series is in G.P.
as 2*3 = 6, 6*3 = 18, 18*3 = 54
So a = 2 , r = 3
nth term in G.P. is
\begin{aligned}
ar^{n-1} \\
= 2*3{8-1} \\
= 2*3^7 \\
= 2*2187 = 4374
\end{aligned}

Similar Questions :

1. 4, 10, (?), 82, 244, 730

  • 26
  • 28
  • 40
  • 48

Answer: Option B

Explanation:

Each number in the series is the preceding number multiplied by 3 and then decreased by 2.

2. Which fraction will come next, \begin{aligned} \frac{1}{2}, \frac{3}{4}, \frac{5}{8}, \frac{7}{16}, ? \end{aligned}

  • \begin{aligned} \frac{11}{32} \end{aligned}
  • \begin{aligned} \frac{9}{28} \end{aligned}
  • \begin{aligned} \frac{9}{30} \end{aligned}
  • \begin{aligned} \frac{9}{32} \end{aligned}

Answer: Option D

Explanation:

Numerators of the fractions in the given sequence are getting increased by 2, i.e. 1+2,3+2,5+2, so next will be 7+2 = 9

Denominators of the fractions in the series is getting doubled, 2*2 = 4, 4*2 = 8, 8*2 = 16, no next will be 16*2 = 32

So resulting fraction will be
\begin{aligned}
\frac{9}{32}
\end{aligned}

3. 3, 12, 27, 48, 75, 108,

  • 141
  • 143
  • 145
  • 147

Answer: Option D

Explanation:

Series is having pattern
\begin{aligned}
3*1^2, 3*2^2, 3*3^2, ......\\
\text{Next will be } 3*7^2 = 147
\end{aligned}

4. 6, 11, 21, 36, 56, ... ?

  • 81
  • 83
  • 95
  • 105

Answer: Option A

Explanation:

Pattern is +5, +10, +15, + 20. So next will be 56+25 = 81

5. Complete the series
20, 19, 17, ...., 10, 5

  • 15
  • 16
  • 13
  • 14

Answer: Option D

Explanation:

Pattern is, -1, -2, ..,.. , -5

So -3 and -4 will fill the blanks to make it a pattern.

Next number will be 17-3 = 14

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