3 hexagons

northwolves

Place the integers 1 through 28 in the circles of the figure on the left so that each number is used exactly once, the numbers on each edge of each hexagon add to a common sum (there are 15 edges in all), and the numbers at the red corner points are primes.

KeyTo9_Fans

有6个解，这是其中1个： 其余5个是经过镜面对称和旋转得到的，本质上是一样的解。

geslon

Key版主反应太快了。