Determine the next terms of the sequence 3, 3, 9, 6, 15, 12,....

Question

Please help - need to figure out how this sequence works!!

Answer 1

Given sequence 3, 3, 9, 6, 15, 12, .......

The above sequence can be written as two sequenses using the alternative numbers.

First sequence : 3, 9, 15, .....

Second sequence : 3, 6, 12, ....

Pattern of first sequence is just multiply by 1, 3, 5, 7, ....to the first term one by one to find next term.

Therefore the next term of the first sequence is 21.

Pattern of second sequence is just multiply by 2, 4, 6, ..... to the second term one by one to find next term.

Therefore the next term of the second sequence is 18.

Therefore, the sequence is 3, 3, 9, 6, 15, 12, 21, 18, .....

Comments

Sorry, by type mistake

Pattern of second sequence is just multiply by 1, 2, 4, 6, ..... to the first term(3) one by one to find next term.

Therefore the next term of the second sequence is 18.

Therefore, the sequence is 3, 3, 9, 6, 15, 12, 21, 18, .....

Answer 2

Here is the answer for sequence 3, 0, 9, 6, 15, 12

Represent the series as two series combination

3, 9, 15, ...

0, 3, 6, ....

 

To get the next terms in first sequence multiply it by odd numbers 1, 3, 5, 7, ..

3 x 1, 3 x 3, 3x 5, 3 x 7

3, 9, 15, 21

 

Toget the next terms in secondsequence multiply it by even numbers 0, 2, 4, 6, 8..

3 x 0, 3 x 2, 3x 4, 3 x 8

0, 6, 12, 24

 

Write the combined series

3, 0, 9, 6, 15, 12, 21, 18, 24.....