Sequences

[pinkee]

Can anyone help with the missing numbers (represented by a question mark) below:

12 29 43
47 27 76
79 ? 81

42 (41) 38
23 (??) 28

Thanks

[Calibax]

1) 116? In each column the second entry plus the third minus the first = 114.
47+79-12=114
76+81-43=114
27+116-29=114

[pinkee]

Thank you - thats very clever

[bibblebub]

2) there's probably many answers and one would be to subtract the left number from the right with its digits reversed to get the number in brackets

so take 42 from 83 to get 41
and take 23 from 82 to get 59

[Calibax]

^That looks likely bibblebub. With only one example it's not easy to spot a pattern.

[pinkee]

I've obviously found two people who are good at this kind of thing. What about this one:

7 15 10 ? 14 10 19

[bibblebub]

12 is one possibility

if you take every other number then you have an ascending sequence
7 10 14 19 which has gaps of 3 4 5 i.e. increasing by 1

and the remaining numbers are 15 ? 10 so I'd guess a descending sequence with gaps decreasing by 1 so the missing number is 12 in that case because the gaps would be 3 2

[bibblebub]

instead of thinking of it as a decreasing gap use negative numbers to get increasing gaps (like the 1st sequence) of -3 and -2

[bibblebub]

Alternatively the amount that is being subtracted in the 2nd sequence might be increasing an so 13 would be a possible answer too, There are too few numbers in the puzzle to be sure of one particular solution.

[pinkee]

Thank you.