# Logical Reasoning / Number Series Questions and Answers – III

20 questions on “Logical Reasoning / Number Series Questions and Answers – III” series.

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## Questions Section

Q1. Here is the number series to solve, if:
52 + 88 = 7280
20 + 46 = 1320
44 + 14 = 2552
91 + 3 = ? – what will be the number here?

Answer: 8554 i.e. 91 * (91 + 3)

52 * (52 + 88) = 7280,
20 * (20 + 46) = 1320, 44 * (44 + 14) = 2552
Logic: The logic is addition of both number multiplied by first number i.e.(52 + 88)*52=7280

Q2. Second question in the series is:
88 + 4 = 7392
60 + 75 = -900
92 + 82 = 920
55 + 54 = ? – what will be the number here?

Answer: 55 i.e. 55 * (55 – 54)

88 * (88 – 4) = 7392
60 * (60 – 75) = -900, 92 * (92 – 82) = 920
Logic: The logic is subtraction of both number multiplied by first number i.e.(88 – 4)*88=7392

Q3. Third question in the series is:
74 + 84 = 232
13 + 66 = 92
81 + 2 = 164
19 + 14 = ? – what will be the number here?

Answer: 52 i.e. 19*2 + 14

74*2 + 84 = 232
13*2 + 66 = 92, 81*2 + 2 = 164
Logic: The logic is 2 multiplied by first number plus second number i.e.(74*2 + 84)=232

Q4. What is the next number in the series:

38, 19.0, 9.5, 4.75, ?

: 2.375 i.e. 4.75/2.
Logic: Second number is half of first one, 3rd number is half of second one and so on i.e. 38/2 =19.0, 19.0/2 =9.5, 9.5/2 =4.75 and so on.

Q5. Guess next number in the series:

44, 22.0, ??, 5.5, 2.75

: 11.0 i.e. 22.0/2.
Logic: Second number is half of first one, 3rd number is half of second one and so on i.e.44/2 = 22.0, 22.0/2 = 11.0, 11.0/2 =5.5 and so on.

Q6. Guess next number in the series:

4, 16 , 64 , 256 , ?

: 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, 36, ??, 1296, 7776

: 216 i.e.6^3
Logic: The series is square, cube, ^4 and so on i.e. 6*6 = 36, , 66*6 = 216 etc.

Q8. Guess next number in the series:
9, 10, 12, 15, ?

Ans.19 i.e. 15 + 4
Second number is (1st number + 1), third number is (2nd number + 2), 4th is (3rd number + 3) and so on.
i.e. 9 + 1 = 10, 10 + 2 = 12, 12 + 3 = 15 and so on.

Q9. What will be the next number in the series:
7, 9, 13, 19, ?

Ans. 27 i.e. 12 + 8
Second number is (1st number + 2), third number is (2nd number + 4), 4th is (3rd number + 6) and so on.
7 + 2 = 9, 9 + 4 = 13, 13 + 6 = 19 and so on.

Q10. Find the missing number in the series:
0, 2, ??, 12, 20

Ans. 6 i.e. 2 + 4
0 + 2 = 2, 2 + 4 = 6, 6 + 6 = 12, 12 + 8 = 20,
Logic: Second number is (1st number + 2), third number is (2nd number + 4), 4th is (3rd number + 6) and so on.

Q11. 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.

Q12. Identify the missing number in the series:
26, 29, ??, 38, 44, 51

Ans. 33 i.e. 29 + 4
26 + 3 = 29, 29 + 4 = 33, 33 + 5 = 38, 38 + 6 = 44, 44 + 7 = 51.
Logic: First number + 3 = 2nd number, second number + 4 = 3rd number, third number + 5 = 4th number and so on.

Q13. Find the missing number in the series:
26, 26, ??, 156, 624, 3120

Ans. 52 i.e. 26*2=52
26*1 = 26, 26*2 = 52, 52*3 = 156, 156*4 = 624, 624*5 = 3120.
Logic: First number*1 = 2nd number, second number*2 = 3rd number, third number*3 = 4th number and so on.

Q14. 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.

Q15. Find the missing number in the series:
4, 10, 15, ??, 25, 30

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.

Q16. A car crosses a 1720 m long road in 2 minutes. What will be it’s speed in km per hour?
Options:A. 17.028, B. 25.8, C. 30.96, D. 51.6

Answer: 51.6 km/h i.e. [(1720/1000) / (2/60)]
Logic: Converting 1720 to kilometer by dividing it by 1000 and converting 2 to hour by dividing it by 60 and dividing both.

Q17. 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.

Q18. Next number in the series is:

26, 24, 20, 18, 14, ??

Ans
: 12 i.e. 14 – 2 = 12
26, 26 – 2 = 24, 24 – 4 =20 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.

Q19. Next number in the series is:

6, 5 , 7, 6, 8, ??

Ans
: 7 i.e. 8 – 1 = 7
6, 6 – 1 = 5, 5 +2 =7 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.

Q20. Next number in the series is:

38, 38, 27, 27, 16, ??

Ans
: 16 i.e. 27 – 11 = 16
38, 38, 38 -11 = 27, 38 -11 = 27 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.