Sequence and Series Questions and Answers Part-5

Data for Questions 1 & 7 : In each of the following number series a wrong number is given. Find out the wrong number

1. 31, 22, 30, –32, –89, –174
a) 22
b) 30
c) -32
d) -89

Answer: b
Explanation: Obviously 30 is the misplaced number because all other terms are in a reducing series here. Option (b) is correct.

2. 4, 26, 163, 1149, 9201, 82809
a) 26
b) 163
c) 82809
d) 9201

Answer: c
Explanation: The logic followed in this series is 4 ¥ 5 + 6 = 26; 26 ¥ 6 +7 = 163; 163 ¥ 7 + 8 =1149; 1149 ¥ 8 + 9 = 9201. Only the last number in the series (82809) breaks this trend. Instead the correct value should have been 9201 ¥ 9 + 10 = 82819. Thus, Option (c) is correct.

3. 4, 39, 269, 1605, 8009, 32011
a) 4
b) 39
c) 269
d) 1005

Answer: a
Explanation: The logic followed in this series is 39 ¥ 7 – 4 = 269; 269 ¥ 6 – 9 = 1605; 1605 ¥ 5 –16 = 8009; 8009 ¥ 4 – 25 = 32011. Only the movement from 4 to 39 is unexplained by this trend. Thus, 4 is the incorrect number in the series. Option (a) is correct.

4. 28, 84, 112, 196, 308, 504, 872
a) 112
b) 196
c) 308
d) 872

Answer: d
Explanation: The logic of this series is that the sum of two numbers makes the third one in the series. This we can observe by seeing 28+84=112, 84+112=196 and so on. The only number that does not satisfy this logic is 308+504, which should be 812 and not 872. Thus, 872 is the wrong number in the series.

5. 14, 20, 369, 1288, 12961, 155432
a) 14
b) 20
c) 369
d) 1288

Answer: c
Explanation: The logic is 14 ¥ 4 – 36 = 20; 20 ¥ 6 + 49 =169; 169 ¥ 8 –64 = 1288, 1288 ¥ 10 + 81 = 12961; 12961 ¥ 12 –100 = 155532. Obviously, the incorrect value in the series is 369 and Option (c) is the correct answer.

6. 14400, 7200, 4800, 3600, 2800, 2400
a) 7200
b) 4800
c) 2800
d) 2400

Answer: c
Explanation: The logic of the series is 14400 ¥ ½ = 7200, 7200 ¥ 2/3 = 4800, 4800 ¥ 3/4 = 3600, 3600 ¥ 4/5 = 2880. Obviously the number 2800 is out of place. Option (c) is correct

7. 300, 421, 592, 815, 1104, 1465
a) 421
b) 1105
c) 815
d) 592

Answer: c
Explanation: The logic of the additions are 121,171, 221, 291, 361 and so on. Thus, the number series should be 300, 421, 592, 813, 1104,1465. The number 815 is misplaced in the above series and hence Option (c) is incorrect

Data for Questions 8 & 10 : Study the following information carefully to answer the questions given below: S Q A 5 N % T 7 B 4 # J E $ 2 T D * 1 8 H 3 U @ 9 F W © K

8. How many such consonants are there in the above arrangement, each of which is immediately followed by a vowel but not immediately preceded by a number?
a) One
b) Two
c) Three
d) More than three

Answer: a
Explanation: T7 is the only instance of a consonant followed by a number and not preceded by a number. Option (a) is correct

9. How many such consonants are there in the above arrangement, each of which is either immediately preceded by a vowel or immediately followed by a symbol but not both?
a) None
b) One
c) Two
d) Three

Answer: b
Explanation: 5N% is the only instance of a consonant either followed by a symbol or preceded by a vowel but not both. Option (b) is correct

10. Which of the following is the seventh to the left of the fifteenth from the left end in the above arrangement?
a) H
b) B
c) 1
d) 7

Answer: d
Explanation: The fifteenth from the left is ‘2’ while the 7th to the left of 2 is ‘7’ itself. Option (d) is correct.