# Number Series Questions and Answers

## Number Series Question and Answers

Go through the entire page to solve Number Series Questions and Answers easily.

A Number series is the total of all the numbers of numbers produced out of some pattern or trend.

All term in the sequence meet a specific logical rule which needs to be recognized in order to find the missing terms.

## Types of Number Series Problems –

• Add up Series (+) :  Just adding a constant number everytime. For example:  (13, 18, 23, 28 ….).

• Add up Series (- ):  , Just subtracting a constant number every time. For example : (28, 23, 18, 13 ……).

• Step up Series (+/-) :  Adding/Subtracting a variable number, in this case we are adding 2n for n = 0, 1, 2, 3 …… For example : 0, 2, 6, 12, 20…. or 20, 12, 6, 2, 0, 0 …..

• Square up (+/-) –  Given series is in the square of n where  n= 1,2,3,4,5,6… i.e. 1,4,9,16,25,36…

• Square add up Series(+/-) : Adding n2 every time and incrementing value of n starting from 1 i.e. 1,5, 14, 30, 55, ……  and Subtracting n2 every time and decrementing value of n i.e. 34, 33, 29, 20,

• Cube Up Series : Given series is in the cube of n where n = 1,2,3,4,5,6… i.e. 1,8,27,64,125,216….

• Cube add up Series : Adding n3 every time with incrementing of n by 1 i.e. 1,9,36…

• Prime up(+/-) : Sequence consist of Prime numbers i.e. 2,3,5,7,11…

• Prime Square up(+/-) : Sequence consist of squares of prime numbers i.e. 4,9,25,49,121..

• Arithmetic Series: Sequence consist of Arithmetic Progression i.e. 3,6,9,…

• Geometric Series : Sequence consist of Geometric Progression i.e. 2,6,18,54,…

For example,
‘2+4+6+8+10’ is a number series – the sum of the first five even numbers or the multiples of 2.

Most of the competitive exams or management aptitude tests frequently asked questions based on number series. In Number Series the examine would be given a particular sequence in which he’s to analyze the pattern followed by the said series and accordingly he would be asked to foretell the following number of the series following the same trend or pattern.

### Types of Number Series

• Series with increasing difference
• Series with a constant difference
• Series with decreasing difference
• Combination of different operations, like ‘+’ and ‘-’ together, etc.
• Perfect squares and cubes of numbers’ series
• Miscellaneous

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## Number Series Questions with solved examples

1. Directions to Solve

Choose the correct alternative that will continue the same pattern

132 131 132 129 132 127 132

125

125

89.63%

131

131

4.53%

129

129

2.84%

127

127

3%

This is an alternating repetition series. The number 132 alternates with a series in which each number decreases by 2.
Hence the number is 125.

2. Directions to Solve

Choose the correct alternative that will continue the same pattern and find out the wrong/odd number from the given series.

110 120 125 135 140 150 155

170 165

170 165

5.75%

160 170

160 170

10.89%

160 175

160 175

5.31%

160 165

160 165

11.23%

165 170

165 170

66.81%

This is an alternating addition series, in which 10 is added, then 5. Hence option E is correct.

3. Explanation: This is an alternating repetition series. The number 132 alternates with a series in which each number decreases by 2.

240 240 231 231 222 222 213

213 204

213 204

83.13%

213 205

213 205

10.32%

204 213

204 213

4.6%

209 214

209 214

1.96%

This is a subtraction series with repetition. Each number repeats itself and then decreases by 9. Hence option A is correct.

4. Directions to Solve

Choose the correct alternative that will continue the same pattern and find out the wrong/odd number from the given series.

117 117 134 120 120 131 123

126 123

126 123

6.24%

134 120

134 120

5.99%

123 133

123 133

18.76%

123 128

123 128

69.01%

This is an alternating subtraction series with repetition. This follows two different patterns. In the first series, a number repeats itself; then 3 is added to that number to get the next number, which will also repeat. Every 3rd number follows a second pattern, in which 3 is subtracted from each number to arrive at the next number.

5. Directions to Solve

Choose the correct alternative that will continue the same pattern and find out the wrong/odd number from the given series.

5, 15, 45, 135, 600, 2025, 6075

600,18225

600,18225

58.74%

2025,4567

2025,4567

18.42%

600, 1100

600, 1100

19.27%

13, 12

13, 12

3.57%

the series goes as each number is multiplied by 3 hence instead of 600 it must be 675 .

6. Directions to Solve

Choose the correct alternative that will continue the same pattern and find out the wrong/odd number from the given series.

161 157 150 161 143 136 161

129 161

129 161

27.13%

127 120

127 120

18.78%

122 115

122 115

6.32%

129 122

129 122

47.77%

This is an alternating repetition series, in which a random number, 161, is inserted as every third number. Starting with the second number, 157, each number (except 161) is 7 less than the preceding number.

7. Directions to Solve

Choose the correct alternative that will continue the same pattern and find out the wrong/odd number from the given series.

109 116 123 130 137 144 151

159 166

159 166

6.66%

156 162

156 162

4.73%

158 166

158 166

13.14%

158 165

158 165

75.47%

Here is a simple addition series, which begins with 109 and adds 7.

8. Directions to Solve

Choose the correct alternative that will continue the same pattern and find out the wrong/odd number from the given series.

18 22 22 26 30 22 34

38 32

38 32

15.09%

38 22

38 22

60.79%

22 38

22 38

17.89%

32 36

32 36

6.24%

This is an alternating repetition series, in which a random number, 22, is inserted as every third number. In the addition series, 4 is added to each number to arrive at the next number.

9. Directions to Solve

Choose the correct alternative that will continue the same pattern and find out the wrong/odd number from the given series.

18 21 21 25 28 21 32

35 18

35 18

8.08%

35 21

35 21

79.44%

35 29

35 29

6.98%

34 21

34 21

5.49%

This is an alternating addition series, by adding a random number, 21, inserted as every third number. The addition series added two numbers as 4 and 3.

10. Directions to Solve

Choose the correct alternative that will continue the same pattern and find out the wrong/odd number from the given series.

1225, 1224, __, 1222, 1221

1220

1220

2.24%

1223

1223

94.91%

1219

1219

1.7%

1226

1226

1.15%

The given numbers are consecutive natural numbers in decreasing order starting with 1225. Hence, the missing number is 1223.

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