## number series #### Discussion Question

In each series, look for the degree and direction of change between the numbers. In other words, do the numbers increase or decrease, and by how much

###### Look at this series: 2, 1, (1/2), (1/4), ... What number should come next?
 A (1/3) B (1/8) C (2/8) D (1/16)
 ANS: B - (1/8)

This is a simple division series; each number is one-half of the previous number. In other terms to say, the number is divided by 2 successively to get the next result.

```4/2 = 2
2/2 = 1
1/2 = 1/2
(1/2)/2 = 1/4
(1/4)/2 = 1/8 and so on.```

###### Look at this series: 7, 10, 8, 11, 9, 12, ... What number should come next?
 A 7 B 10 C 12 D 13
 ANS: B - 10

This is a simple alternating addition and subtraction series. In the first pattern, 3 is added; in the second, 2 is subtracted

###### Look at this series: 36, 34, 30, 28, 24, ... What number should come next?
 A 20 B 22 C 23 D 26
 ANS: B - 22

This is an alternating number subtraction series. First, 2 is subtracted, then 4, then 2, and so on.

###### Look at this series: 22, 21, 23, 22, 24, 23, ... What number should come next?
 A 22 B 24 C 25 D 26
 ANS: C - 25

 In this simple alternating subtraction and addition series; 1 is subtracted, then 2 is added, and so on

###### Look at this series: 53, 53, 40, 40, 27, 27, ... What number should come next?
 A 12 B 14 C 27 D 53
 ANS: B - 14

In this series, each number is repeated, then 13 is subtracted to arrive at the next number.

###### Look at this series: 21, 9, 21, 11, 21, 13, 21, ... What number should come next?
 A 14 B 15 C 21 D 23
 ANS: B - 15

In this alternating repetition series, the random number 21 is interpolated every other number into an otherwise simple addition series that increases by 2, beginning with the number 9

###### Look at this series: 58, 52, 46, 40, 34, ... What number should come next?
 A 26 B 28 C 30 D 32
 ANS: B - 28

This is a simple subtraction series. Each number is 6 less than the previous number.

###### Look at this series: 3, 4, 7, 8, 11, 12, ... What number should come next?
 A 7 B 10 C 14 D 15
 ANS: D - 15

This alternating addition series begins with 3; then 1 is added to give 4; then 3 is added to give 7; then 1 is added, and so on.

###### Look at this series: 8, 22, 8, 28, 8, ... What number should come next?
 A 9 B 29 C 32 D 34
 ANS: D - 34

This is a simple addition series with a random number, 8, interpolated as every other number. In the series, 6 is added to each number except 8, to arrive at the next number.

###### Look at this series: 31, 29, 24, 22, 17, ... What number should come next?
 A 14 B 15 C 13 D 12
 ANS: B - 15

This is a simple alternating subtraction series, which subtracts 2, then 5.

###### Look at this series: 1.5, 2.3, 3.1, 3.9, ... What number should come next?
 A 4.2 B 4.4 C 4.7 D 5.1
 ANS: C - 4.7

In this simple addition series, each number increases by 0.8.

###### Look at this series: 14, 28, 20, 40, 32, 64, ... What number should come next?
 A 52 B 56 C 96 D 128
 ANS: B - 56

This is an alternating multiplication and subtracting series: First, multiply by 2 and then subtract 8.

###### Look at this series: 2, 4, 6, 8, 10, ... What number should come next?
 A 11 B 12 C 13 D 14
 ANS: B - 12

This is a simple addition series. Each number increases by 2.

###### Look at this series: 201, 202, 204, 207, ... What number should come next?
 A 205 B 208 C 210 D 211
 ANS: D - 211

In this addition series, 1 is added to the first number; 2 is added to the second number; 3 is added to the third number; 4 is added to the fourth number; and go on.

###### Look at this series: 544, 509, 474, 439, ... What number should come next?
 A 404 B 414 C 420 D 445
 ANS: A - 404

This is a simple subtraction series. Each number is 35 less than the previous number.

###### Look at this series: 80, 10, 70, 15, 60, ... What number should come next?
 A 20 B 25 C 30 D 50
 ANS: A - 20

This is an alternating addition and subtraction series. In the first pattern, 10 is subtracted from each number to arrive at the next. In the second, 5 is added to each number to arrive at the next.

###### Look at this series: 2, 6, 18, 54, ... What number should come next?
 A 108 B 148 C 162 D 216
 ANS: C - 162

This is a simple multiplication series. Each number is 3 times more than the previous number.

###### Look at this series: 5.2, 4.8, 4.4, 4, ... What number should come next?
 A 3 B 3.3 C 3.5 D 3.6
 ANS: D - 3.6

In this simple subtraction series, each number decreases by 0.4.

###### Look at this series: 8, 6, 9, 23, 87 , ... What number should come next?
 A 128 B 226 C 324 D 429
 ANS: D - 429

8 x 1 - 2 = 6
6 x 2 - 3 = 9
9 x 3 - 4 = 23
23 x 4 - 5 = 87
87 x 5 - 6 = 429 ... 