# Finding pattern of numbers

I have this puzzle for adding 2 numbers (Or sequences)

Does anyone have an idea about how this addition works? $$5+1=9\\3+1=10\\5+2=21\\8+2=23\\9+0=28\\4+3=??$$

• Care to tell us where this puzzle comes from? – Gareth McCaughan Nov 28 '17 at 22:34
• in fact my friend send it to me – user11618 Nov 28 '17 at 22:56
• may be $$4 + 3 = 31$$ – Mandar Nov 29 '17 at 13:52
• @Mozfox how is that ? – user11618 Nov 29 '17 at 22:16

I think the answer can be

21

Reason

6=9 //5+1=9
4=10 //3+1=10
7=21 //5+2=21
10=23 //8+2=23
9=28 //9+0=23
7=21 //4+3=21 as already given of 5+2=21

• For your second line, it's actually 3+1=10, not 3+2. – Lolgast Nov 30 '17 at 8:15
• I don't think it's that easy – user11618 Nov 30 '17 at 11:19
• @user11618 any hint – rudra Nov 30 '17 at 11:20
• @rudra I don't know why I got downvoted :3 , but I don't think your answer is right – user11618 Nov 30 '17 at 19:01
• @user11618 You are downvoted because this is completely random. And the formula submitted by you is not matching with the statement – rudra Dec 1 '17 at 1:56

3+1 = 10 is what’s given. So

4 = 10

8+2 = 23. So 10 = 23.

5+2 = 21. So 7 = 21.

3 = 10-7 = 23 - 21 = 2

Therefore,

4+3 = 10+2 = 12

This seems quite improbable but well who knows?

Thanks every body, I've found the solution.
$$5+2=21 \\ 5^2+2^5+(5+2)!=5097 \to 5+0+9+7 = 21\\ x+y = ?\\ x^y + y^x +(x+y)! = abcd \to s= a+b+c+d$$

• First of all, this is completely random and so far-fetched that I don't believe it's actually solvable. – Levieux Nov 30 '17 at 13:02
• Secondly, you've made a mistake: 5^1+1^5+(5+1)!=5+1+720=726 -> 15. Probably 120 was erroneously used instead of 720 by the creator of this puzzle... – Levieux Nov 30 '17 at 13:02

Given the formula I get:

$$4 ^ 3 + 3 ^ 4 + (4 + 3)! = 5185$$
$$5 + 1 + 8 + 5 = 19$$