## Sequence and Series Questions and Answers Part-4

1. 1, 3, 2, 5, 3, 7, 4, 9, 5, 11, 6, ?
a) 10
b) 11
c) 13
d) 9

Explanation: Two series are intermixed. 1, 2, 3, 4, 5, 6 and 3, 5, 7, 9, 11. Hence, the next term should be 13. So option (c) is the answer

2. 1, 4, 27, ?
a) 256
b) 3125
c) 2425
d) none of these

Explanation: The general term of the series is nn. Hence, the next term in the series would be 44 = 256. Option (a) is the answer.

3. What is the next term in the following series?
ABE, BCF, CDG, DEH, EFI, ______
a) FGK
b) FGJ
c) FGL
d) none of these

Explanation: The next term in the series would be FGJ. Hence, option (b) is the answer

4. What is the next term in the following series?
ZYXWTSRQNMLK
a) I
b) G
c) H
d) J

Explanation: The given series starts with the last 4 alphabets of the English language and then gives a breakof 2 alphabets, followed by the next four alphabets and so on. Hence, the next term in the series would be H (after skipping J and I). So option (c) is the answer

5. What is the sum of infinite terms of the given series?
$4+4¥4^{1/2}+4¥4^{1/2}¥4^{1/4}+$       ______ .
a) 12
b) 16
c) 64
d) none of these

Explanation: On close observation of the series you will realise that every subsequent term reduces in value from the previous term. Hence, by estimating values we can estimate that the sum of this series to infinite terms would be 16. The correct answer is option (b).

6. What is the next term in the following series?
1, 4, 3, 9, 5, 16, 7, 25, 9, 36, 11, ?
a) 64
b) 49
c) 48
d) 55

Explanation: Two series are intermingled with each other as 1, 3, 5, 7, 9, 11 and 22, 32, 42, 52, 62. Hence, the next term in the series would be 72 = 49, so the correct answer is option (b)

7. Calculate the sum of the series
1 + 1/4 + 1/16 + ______.
a) 3/4
b) 4/3
c) 2
d) none of these

Explanation: Infinite GP with common ratio 1/4. Hence, Sum to infinity = 1/(3/4) = 4/3. Answer is option(b).

8. Calculate the missing term.
625, 125, ?, 5, 1
a) 1/5
b) 1
c) 5
d) none of these

Explanation: GP with common ratio 1/5. Hence, option (d) is correct.

9. Obtain the missing term.
300, 296, 287, 271, ?, 210
a) 246
b) 250
c) 244
d) none of these