If you’re anything like me, you’ll be thankful that the last time you had to work out a vexing math sum or tackle an algebraic problem was way back in high school.
I know some people have a natural affinity for math, while others (myself included) seem to have an aversion to it. Personally, I like to think of myself as a creative spirit rather than a numbers person, but hey, we all have our strengths!
That being said, despite my earlier disdain for math classes crowded with distractions, I’ve found a surprising enjoyment in solving online puzzles and riddles. Of course, I do this in my own time—there’s no rush. But there’s something oddly satisfying about cracking these brain-teasers, especially when it comes to tricky problems on the internet.
And I’m definitely not alone in this. It seems there’s a whole community of people out there who love hunting down patterns and solving tough math problems. So, why not put our readers’ minds to the test with one that’s been stumping many across the web?
Got your thinking cap on? Ready for a mental workout? Here we go:
If 1+4=5, 2+5=12, and 3+6=21, then what is 5+8?
Let’s break it down:
1 + 4 = 5
2 + 5 = 12
3 + 6 = 21
5 + 8 = ?
This problem has the internet buzzing, with many unsure of the right approach. The key is how you interpret the pattern—there are multiple ways to solve it!
The twist? There isn’t just one solution! In fact, there are several possible answers, depending on how you look at it. If you’ve tried solving it yourself and want to know if you’re on the right track (or if you’re feeling frustrated and need the answer), keep reading for five different ways to crack it.
Solution 1: 1 + 4 = 5
2 + 5 = 2 + 2(5) = 12
3 + 6 = 3 + 3(6) = 21
5 + 8 = 5 + 5(8) = 45
Algorithm: A + A(B) = C
Answer: 45
Solution Two:
1 + 4 = 1 + 4 + (0) = 5
2 + 5 = 2 + 5 + (5) = 12
3 + 6 = 3 + 6 + (12) = 21
5 + 8 = 5 + 8 + (21) = 34
Algorithm: A + B + C’ = C, where C’ is the previous answer.
Answer: 34
Solution Three:
1 + 4 = 5
2 + 5 = (5 + 2) + (5) = 12
3 + 6 = (7 + 2) + (12) = 21
5 + 8 = (9 + 2) + (21) = 32
Algorithm: for {X=5, C = X + C’, X = X+2}; where C’ is the previous answer. A and B are not used in the equation.
Answer: 32
Solution Four:
1 + 4 = 5
2 + 5 = 7 (base 5) = 12
3 + 6 = 9 (base 4) = 21
5 + 8 = 13 (base 3) = 111
Algorithm: for {X=6, C = (A + B)^(10 -> X), X-1} (First answer in Base 6, then Base 5, then Base 4, etc.)
Answer: 111
Solution Five:
1 + 4 = 5
2 + 5 = 7 (base 5) = 12
3 + 6 = 9 (base 4) = 21
4 + 7 = 11 (base 3) = 102
5 + 8 = 13 (base 2) (aka binary) = 1101
Algorithm: for {X=6, C = (A + B)^(10 -> X), X-1} (First answer in Base 6, then Base 5, then Base 4, etc., including “missing” numbers)
Answer: 1101
