Change-the-order-of-numbers-on-a-clock-dial-so-that-sum-of-any-two-numbers-of-consecutive-positions-may-be-prime-

Question Number 3146 by Rasheed Soomro last updated on 06/Dec/15

C h a n g e t h e o r d e r o f n u m b e r s o n a c l o c k - d i a l s o t h a t

s u m o f a n y t w o n u m b e r s o f c o n s e c u t i v e p o s i t i o n s m a y

b e p r i m e .

Answered by prakash jain last updated on 06/Dec/15

1 \to 2, 4, 6, 12

2 \to 1, 3, 5, 11

3 \to 2, 4, 8, 10

4 \to 1, 3, 7, 9

5 \to 2, 6, 8, 12

6 \to 1, 5, 7, 11

7 \to 4, 6, 10, 12

8 \to 3, 5, 9, 11

9 \to 2, 4

10 \to 3, 7, 9

11 \to 2, 6, 8, 12

12 \to 1, 5, 7, 11

9 10 3 2 1 4 7 6 5 12 11 8

9 \to 19 17

10 \to 19 13

3 \to 11 5

2 \to 5 3

1 \to 3 5

4 \to 5 11

7 \to 11 13

6 \to 13 11

5 \to 11 17

12 \to 17 23

11 \to 23 19

8 \to 19 17

Commented by prakash jain last updated on 06/Dec/15

Thanks . Corrected .

Commented by RasheedAhmad last updated on 06/Dec/15

V V N i c e!

I n 3^{r d} l i n e I t h i n k^{'} 1^{'} s e e m s

m i s t a k e n l y

i n c l u d e d .

3 \to \underline{1}, 2, 4, 8; 3 + 1 = 4 \in P

Commented by RasheedAhmad last updated on 06/Dec/15

H o w m a n y s o l u t i o n s m a y b e ?