2007-01-02 11:17:43 · 9 answers · asked by Kymberlee M 1 in Science & Mathematics ➔ Mathematics
I agree that the likely answer is 18, from adding the prior two terms.
However, another interpretation is to look at the following:
Primes: 2 3 5 7 11 13 17 19 23 29 31 37 41
Composites: 4 6 8 9 10 12 14 15 16 18 20 21 22
nth prime minus nth composite:
2 - 4 --> -2
3 - 6 --> -3
5 - 8 --> -3
7 - 9 --> -2
11 - 10 --> 1
13 - 12 --> 1
17 - 14 --> 3
19 - 15 --> 4
23 - 16 --> 7
29 - 18 --> 11
31 - 20 --> 11 <-- next number
37 - 21 --> 16
41 - 22 --> 19
etc.
This points out there are multiple possible answers to a sequence question. However, there is probably one *intended* answer which would be 18 (sum of 7 + 11).
2007-01-02 11:31:21 · answer #1 · answered by Puzzling 7 · 1⤊ 0⤋
1+3 = 4
2+4 = 7
4+7 = 11
7+11= 18
Bozo
2007-01-02 11:20:06 · answer #2 · answered by bozo 4 · 1⤊ 0⤋
18
2007-01-02 11:33:50 · answer #3 · answered by KBH 2 · 0⤊ 0⤋
18
2007-01-02 11:25:16 · answer #4 · answered by raj 7 · 0⤊ 0⤋
Most likely, the next number is 18. Each member
of the sequence is the sum of the previous two.
This is the start of the Lucas sequence defined by
L_1 = 1, L_2 = 3, L_(n+1) = L_n + L_(n-1).
It is the sequence associated with the the sequence of Fibonacci
numbers.
2007-01-02 12:48:10 · answer #5 · answered by steiner1745 7 · 0⤊ 0⤋
18=
1+3=4;3+4=7;4+7=11;7+11=18
2007-01-02 11:31:58 · answer #6 · answered by Dave aka Spider Monkey 7 · 0⤊ 0⤋
18. Each number in the series is the sum of the previous two numbers.
2007-01-02 11:27:05 · answer #7 · answered by Anonymous · 0⤊ 0⤋
18 ... add the last two terms to get the next.
2007-01-02 11:19:25 · answer #8 · answered by dwobbit 2 · 1⤊ 0⤋
18...29...47...76...
2007-01-02 11:21:07 · answer #9 · answered by Texan Pete 3 · 1⤊ 0⤋