2007-02-05 23:51:37 · 30 answers · asked by asri y 1 in Science & Mathematics ➔ Mathematics
43
1+2=3
3+4=7
7+6=13
13+8=21
21+10=31
31+12=43
2007-02-05 23:54:58 · answer #1 · answered by Anonymous · 3⤊ 0⤋
Idea: There are odd number of numbers left between the given numbers.
Between 1 and 3 2 is left
Between 3 and 7 4,5,6 are left
As we proceed
Between 7 and 13 5 numbers are left
Between 13 and21 7 numbers are left
Between 21 and 31 9 numbers are left
So for our answer 11 numbers should be left
and the following number is our answer
Therefore the next number in the series is 43 which is our answer
2007-02-07 04:37:54 · answer #2 · answered by ram s 1 · 0⤊ 0⤋
43 because 1+2=3+4=7+6=13+8=21+10=31+12=43
2007-02-06 07:58:31 · answer #3 · answered by Anonymous · 1⤊ 0⤋
To find the next number in the series each time you use multiples of two and then add:
1, (2+1), 3,(4+3), 7,(6+7), 13......
Hence, the next number is 43
2007-02-07 17:49:31 · answer #4 · answered by Nadz 1 · 0⤊ 0⤋
Look at the differences between numbers:
3-1 = 2
7-3 = 4
13-7 = 6
21-13 = 8
31-21 = 10
So to get the next number you have to add 12. 31 + 12 = 43.
2007-02-06 07:56:22 · answer #5 · answered by mrfahrenbacher 3 · 2⤊ 0⤋
difference between 3 and 1 is 2
3-1=2
then ,7-3=4
thus difference between successive numbers in the series are multiples of 2.
therefore number next to 31 is 31+12=43
next number=43
2007-02-06 08:20:59 · answer #6 · answered by Get to Know 2 · 0⤊ 0⤋
43
2007-02-06 13:27:28 · answer #7 · answered by shishir sp 1 · 0⤊ 0⤋
43
2007-02-06 12:31:04 · answer #8 · answered by kural_akhi 1 · 0⤊ 0⤋
43
2007-02-06 11:32:56 · answer #9 · answered by gangster r 1 · 0⤊ 0⤋
43
2007-02-06 08:14:34 · answer #10 · answered by LEEANE G 3 · 0⤊ 0⤋
43..
3-1=2
7-3=4
13-7=6 so the difference increases by 2. so 31+10+2=43
2007-02-06 08:07:32 · answer #11 · answered by munya 2 · 1⤊ 0⤋