I see a vertical pattern. Starting with the top number, increment to the middle number is doubled to get the increment to get the bottom number. 4 + 1 = 5 5 + 1×2 = 7 11 + 8 = 19 19 + 8×2 = 35 So for the last column: 67 – 32 = 35 35 – 32×2 = -29 But now, after looking at the link to see if -29 is an answer they offer, I see that you didn’t really write the problem the way it appears on the site. For the on the site, it is the same kind of pattern, but applied horizontally. The difference between the first and second numbers is doubled to get the third number in each row. But you wrote the third series wrong in your question – they have it as 67, 131, ?. (Not 67, 35, ?)