Three unique digits from 1-9 must be used in a particular way to arrive at a specified target number – by multiplying two of the numbers together, and then either adding or subtracting the third unique number to arrive at your target.
By using the formula (a×b)±c, where a b and c are three unique digits from 1-9, one way of arriving at 24 is (5×3)+9. Incredibly, there is only one other way of making 24 when using the above rule. Can you find it?
[Note: (5×3)+9 = 24 and (3×5)+9 = 24 counts as just ONE way.]
The 7puzzle Challenge
The playing board of the 7puzzle game is a 7-by-7 grid containing 49 different numbers, ranging from 2 up to 84.
The 2nd & 5th rows of the playing board contain the following fourteen numbers:
6 7 8 16 17 21 28 48 50 55 63 64 81 84
Which three pairs of numbers all have a difference of 47?
. . . can be found when clicking this.