### June 18, 2010

Today I got an IQTest puzzle on Facebook that I got wrong. I’ve considered it more and I still can’t see what the answer is – though I can tell you it’s not 22. I’m normally pretty good at this sort of thing but this one has me baffled. Maybe I’m over-thinking it or maybe I’m just getting plain dumber as time goes by…

Here’s the question.

Which number should replace the question mark? 14, 19, 22, 6 or 4?

 13 8 3 7 4 1 5 1 8 10 9 2 46 32 26 3 14 ? 11 3

Any ideas?

### 3 Responses to “Facebook IQTest Number Puzzler”

Very interesting puzzle (and nice blog too!). If the numbers in each row are a, b, c, and d, respectively, we have a+b=c*d. For example, 13+8=21=3*7, or 14+?=11*3.

• keyzero Says:

Good grief. So obvious. How didn’t I see this!? I’ll go with the getting older and dumber thesis. Thanks Vlad.

2. Jared Wilson Says:

Another hypothesis is that all the row sums are prime numbers.

(13+8+3+7) = 31
(4+1+5+1) = 11
(8+10+9+2) = 29
(46+32+26+3) = 107
(14+N+11+3) = 28+N

Choose N=14,22,6,4, you get sums 42,50,34,32, none of which are prime, but if you choose N=19, this makes the sum 47, which is prime.

– Jared