Find the next number to complete the sequence 3, - 6, 12, 4, 20,?

13

Step-by-step explanation:

From the sequence above the number has a negative sign, increasing and decreasing at rates not quite understandable unless a proper attention is paid.

The sequence of the above data is the reducing number by the specific value and the add double of same number in the outcome.

Take a look a this

-6-3 = - 9 (the first number is subtracted from the second)

12 - (-6) = 18

4 - 12 = - 8

20 - 4 = 16

From the above one can realize that the outcome of every single linear algebra having the - ve sign will increase by 1 (that means + 1 is added to the previous number with a negative sign.

So to following the sequence, the next number will b - 7

According to given pattern new number should be

x - 20 = - 7

x = - 7 + 20

x = 13

The next number to complete the sequence is 13

Step-by-step explanation:

The sequence of given data is the reducing number by the specific value and the add double of same number in the outcome.

The difference between numbers

-6-3 = - 9

12 - (-6) = 18

4 - 12 = - 8

20 - 4 = 16

The pattern if behaves as

x-n

x-2x

According to given pattern new number should be

x - 20 = - 7

x = - 7 + 20

x = 13

The next umber will be 13