Math sequence problems

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Math sequence problems

Postby BadgerJelly on August 10th, 2017, 3:26 am 

I am sure this are quite easy, but I've forgotten how to work out sequences.

These are both from IQ test I did recently and I got one right without attempting to work it out ...

1) 2 - 3 - 6 - 7 - 8 - 14 - 15 - 30

Which one doesn't belong in series?

2) 1 - 2 - 5 - 10 - 13 - 26 - 29 - 48

Which one doesn't belong in series?

1, 5, 26, 29 or 48?

3) 1 - 8 - 27 - x - 125 - 216

What is x?

36, 45, 46, 64 or 99?

Thanks
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Re: Math sequence problems

Postby Dave_Oblad on August 10th, 2017, 1:35 pm 

Hi..

Guess? I'm a bit rushed.. but here are my answers..

1) = 14 (multiple answers but 14 violates most)
2) = 1 (growing primes with interwoven 3's)
3) = 64 (46 is too small, 99 is too large)

Regards,
Dave :^)

Ps. Do you know the correct answers?
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Re: Math sequence problems

Postby BadgerJelly on August 10th, 2017, 2:12 pm 

1) is 8, it is nothing to do with math really.

edit : Wait I may be wrong! haha!
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Re: Math sequence problems

Postby mitchellmckain on August 10th, 2017, 3:15 pm 

BadgerJelly » August 10th, 2017, 2:26 am wrote:I am sure this are quite easy, but I've forgotten how to work out sequences.

These are both from IQ test I did recently and I got one right without attempting to work it out ...

1) 2 - 3 - 6 - 7 - 8 - 14 - 15 - 30

Which one doesn't belong in series?

8 does not belong.
The pattern is... add one to get the next number then double this number to get the next.

BadgerJelly » August 10th, 2017, 2:26 am wrote:2) 1 - 2 - 5 - 10 - 13 - 26 - 29 - 48

Which one doesn't belong in series?

48 does not belong
The patter is... double to get the next number then add three to that number to get the one after.
The next one in the series should be 58 not 48.

1, 5, 26, 29 or 48?

BadgerJelly » August 10th, 2017, 2:26 am wrote:3) 1 - 8 - 27 - x - 125 - 216

What is x?

64
These are just the cubes of 1, 2, 3, 4, 5, 6, ....

All three took me about five minutes altogether.
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Re: Math sequence problems

Postby Braininvat on August 10th, 2017, 5:39 pm 

Same here, a couple minutes for first and second series.

The last one I just knew as soon as I looked at the series.
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Re: Math sequence problems

Postby Braininvat on August 10th, 2017, 5:55 pm 

And then there's the infamous...

4, 8, 15, 16, 23, 42

(don't worry, there's no algorithm for this set of numbers)

If you never watched the ABC series "Lost," then this doesn't mean anything. Fans may have noticed that two of the numbers form the flight number of the jet that crashed. And that the last is Douglas Adams meaning of life. And that summing the set yields 108, which can also be expressed as "one to the first times two to the second times three to the third."
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