What is the next number in this series 1, 3, 6, 11, 18, 29??

Question

The choices are: 40, 42, 44, 46

I cannot figure this out...I just cannot see the pattern!

Please show how you got it as well...thank you!! And no this is not homework, just a little quiz I am taking for fun :-)

Answer 1

And I see too many patterns.

Here's one that can be used to justify 44 as the choice:

Differences = 2,3,5,7,11,?

Take differences by groups of 2:
2,3 (numbers are consecutive);
next number is 4 (which is skipped) and the next couple is
5,7 (inner difference of 2)
The next expected number is 9, which is skipped, giving us 11 as the start of the next pair.

In the first pair, the difference (of differences) was 1,
In the second pair, the difference was 2 (5 to 7),
therefore in the 3rd pair the difference must be 4
from 11 to 15

Then 29 + 15 = 44.

Answer 2

The answer is 42 - add 13, which is the next prime number after 2, 3, 5, 7, and 11 - which have all been added to the previous numbers.

Answer 3

It looks like the next prime number is being added: +2, +3, +5, +7, +11. So, the next prime is 13, making the next number 29 + 13 = 42.

* * * * *

OK, looking at the other responses, I have to admit I like Raymond's logic to justify 44 as an answer. That's what I hate about these sequence questions -- with a little imagination, you can find alternative answers.

Answer 4

successive differences are: 2, 3, 5, 7, 11. So primes; next is 13 so 29+13 = 42.

Answer 5

42

Answer 6

Its 42, they adding the prime numbers each time: 2, 3,5, 7, 11, 13. So the first number adds two then 3 then 5 etc...hope that makes sense ^__^

Answer 7

The answer is 42.

Answer 8

47

Answer 9

Everyone who has given their answers before me is right. Their reasoning for the answer is correct as well.