Logical Reasoning / Number Series Questions and Answers – IV

19 questions 0n “Logical Reasoning / Number Series Questions and Answers” series Part IV. You can go to homepage to check the other 3 or refer this links Part-I, Part-II etc.

The number series questions are asked every now and then in every competitive exam be it civil services prelims, state civil service exams, Bank PO, RBI, C-TAT etc.

Hope this article helps you in gaining more skills in such questions that can help you in your exams.

Other Similar Articles:

Part – IPart – IIPart– IIIPart – IVPart – V
Part – VIPart – VIIPart – VIIIPart – IXPart – X

Odd Man out: Part – I | Part II.

Questions Section

Q1. Here is the number series to solve, if:
69 + 10 = 5451
13 + 32 = 585
15 + 34 = 735
51 + 71 = ? – what will be the number here?


Answer: 6222 i.e. 51 * (51 + 71)

69 * (69 + 10) = 5451, 13 * (13 + 32) = 585, 15 * (15 + 34) = 735
Logic: The logic is addition of both number multiplied by first number i.e.(69 + 10) * 69 = 5451

Q2. Second question in the series is:
35 + 26 = 315
16 + 32 = -256
41 + 63 = -902
93 + 11 = ? – what will be the number here?

Answer: 7626 i.e. 93 * (93 – 11),

35 * (35 – 26) = 315, 16 * (16 – 32) = -256, 41 * (41 – 63) = -902
Logic: The logic is subtraction of both number multiplied by first number i.e.(35 – 26)*35=315

Q3. Third question in the series is:
52 + 67 = 171
1 + 56 = 58
42 + 28 = 112
65 + 10 = ? – what will be the number here?


Answer: 140 i.e. 65 * 2 + 10

52 * 2 + 67 = 171, 1 * 2 + 56 = 58, 42 * 2 + 28 = 112
Logic: The logic is 2 multiplied by first number plus second number i.e.(52 * 2 + 67) = 171

Q4. What is the next number in the series:

48, 24.0, 12.0, 6.0, ?

Answer: 3.0 i.e. 6.0/2.
Logic: Second number is half of first one, 3rd number is half of second one and so on i.e. 48/2 =24.0, 24.0/2 =12.0, 12.0/2 =6.0 and so on.

Q5. Guess next number in the series:

8, 4.0, ??, 1.0, 0.5


Answer: 2.0 i.e. 4.0/2.
Logic: Second number is half of first one, 3rd number is half of second one and so on i.e.8/2 = 4.0, 4.0/2 = 2.0, 2.0/2 =1.0 and so on.

Q6. Guess next number in the series:

4, 16 , 64 , 256 , ?


Answer: 1024 i.e. 4^5
Logic: The series is square, cube, ^4 and so on i.e. 4*4 = 16 , 44*4 = 64 etc.

Q7. Guess next number in the series:
6, 7, 9, 12, ?


Ans. 16 i.e. 12 + 4
Second number is (1st number + 1), third number is (2nd number + 2), 4th is (3rd number + 3) and so on.
i.e. 6 + 1 = 7, 7 + 2 = 9, 9 + 3 = 12 and so on.

Q8. What will be the next number in the series:
12, 14, 18, 24, ?


Ans. 32 i.e. 12 + 8
Second number is (1st number + 2), third number is (2nd number + 4), 4th is (3rd number + 6) and so on.
12 + 2 = 14, 14 + 4 = 18, 18 + 6 = 24 and so on.

Q9. Find the missing number in the series:
1,3 ,?? ,13 ,21


Ans. 7 i.e.3 + 4
1 + 2 = 3, 3 + 4 = 7 , 7 + 6 = 13 , 13 + 8 = 21
Logic: Second number is (1st number + 2), third number is (2nd number + 4), 4th is (3rd number + 6) and so on.

Q10. Identify the missing number in the series:
28,31 ,?? ,37 ,40,43


Ans. 34 i.e. 31 + 3
28 + 3 = 31 , 31 + 3 = 34, 34 + 3 = 37, 37 + 3 = 40
Logic: Second number is (1st number + 3), third number is (2nd number + 3), 4th is (3rd number + 3) and so on .i.e. every other number is previous number plus 3.

Q11. Identify the missing number in the series:
16, 19 , ?? , 28 , 34 , 41


Ans. 23 i.e.19 + 4
16 + 3 = 19 , 19 + 4 = 23 , 23 + 5 = 28 , 28 + 6 = 34 , 34 + 7 = 41.
Logic: First number + 3 = 2nd number, second number + 4 = 3rd number, third number + 5 = 4th number and so on.

Q12. Find the missing number in the series:
14 , 14 , ?? , 84 , 336 , 1680


Ans. 28 i.e. 14*2 = 28

14*1 = 14 , 14*2 = 28 , 28*3 = 84 , 84*4 = 336, 336*5 = 1680.
Logic: First number x 1 = 2nd number, second number x 2 = 3rd number, third number x 3 = 4th number and so on.

Q13. Find the missing number in the series:
24,49 ,73 ,?? ,121,145


Ans. 97 i.e. (24*4 + 1) = 97.

24*2 + 1 = 49 , 24*3 + 1 = 73 , 24*4 + 1 = 97 , 24*5 + 1 = 121 , 24*6 + 1 = 145.
Logic: 1st number *2 + 1 = second, 1st number * 3 + 1 = third and so on.

Q14. Find the missing number in the series:
4 , 10 , 15 , ?? , 25 , 30


Ans. 20 i.e. (4^4+4) = 20,

4^2 + 2 = 10, 4^3 + 3 = 15, 4^4 + 4 = 20, 4^5 + 5 = 25, 4^6 + 6 = 30.
Logic: 1st number *2 + 2 = second, 1st number * 3 + 3 = third, 1st number * 4 + 4 = fourth and so on.

Q15. A car crosses a 1600 m long road in 4 minutes. What will be it’s speed in km per hour?

A. 7.92,
B. 12
C. 14.4
D. 24

Answer: 24.0 km/h i.e. [(1600/1000) / (4/60)]
Logic: Converting 1600 to kilometer by dividing it by 1000 and converting 4 to hour by dividing it by 60 and dividing both.

Q16. Next number in the series is:

8 , 11 , 9 , 12 , 10 , ??


Ans: 13 i.e. 10 + 3 = 13
8 , 8 + 3 = 11 , 11 – 2 =9 and so on i.e. +3 and then -2 in alternate numbers.
Logic: This is a simple alternating addition and subtraction series. In the first pattern, 3 is added; in the second, 2 is subtracted and so on.

Q17. Next number in the series is:

20 , 18 , 14 , 12 , 8 , ??


Ans: 6 i.e. 8 – 2 = 6
20 , 20 – 2 = 18 , 18 – 4 =14 and so on i.e. -2 and then -4 in alternate numbers.
Logic: This is a simple alternating subtraction series. In the first pattern, 2 is subtracted; in the second, 4 is subtracted and so on.

Q18. Next number in the series is:

28 , 27 , 29 , 28 , 30 , ??


Ans: 29 i.e. 30 – 1 = 29
28 , 28 – 1 = 27 , 27 + 2 =29 and so on i.e. -1 and then +2 in alternate numbers.
Logic: This is a simple alternating subtraction series. In the first pattern, 1 is subtracted; in the second, 2 is added and so on.

Q19. Next number in the series is:

30 , 30 , 19 , 19 , 8 , ??


Ans: 8 i.e. 19 – 11 = 8
30 , 30 , 30 -11 = 19 , 30 -11 = 19 and so on i.e. same number is repeated twice and then 11 is subtracted from it..
Logic: This is a simple alternating subtraction series. After repeating same number twice 11 is subtracted from it.

Other relevant links:

Conclusion

Please let us know if this is of any help or you want us to improve anything. We will be more than happy to help you in anyway possible.

Thanks.