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Whether it’s possible to construct a magic square using the first nine prime numbers (here counting 1 as prime):
1 2 3 5 7 11 13 17 19
Is it?
Find the possibility here!
What was the task given?
That's impossible task. All the listed prime numbers sums together to 78. For square to be magic, sum of each row & column must be equal. In this case, it should be 78/3 = 26.
For sum of 3 to be even, 1 must be even & other 2 odd (or all even). All 3 odd can't sum even.
In listed prime numbers there is only 1 even number i.e.2. Hence, for other 2 rows/columns we can't have even sum.
There is an Island of puzzles where numbers 1 - 9 want to cross the river.
There is a single boat that can take numbers from one side to the other.
However, maximum 3 numbers can go at a time and of course, the boat cannot sail on its own so one number must come back after reaching to another side.
Also, the sum of numbers crossing at a time must be a square number.
You need to plan trips such that minimum trips are needed.
This should be that minimum number!
What was the challenge?
We need only 7 trips to send all digits across the river.
1. Send 2, 5, 9 (sum is 16).
2. Bring back the 9.
3. Send 3,4, 9 (sum is 16).
4. Bring back the 9.
5. Now send 1,7,8 (sum is 16).
6. Bring back the 1.
7. And finally send 1,6,9 (sum is 16).
