. . . is to arrive at the target number of 18 by adding together exactly FIVE numbers. You are limited to using digits 1 to 5 but these can be used any number of times in each calculation.
One way of making 18 is 5+5+5+2+1 (or 55521 to save time), so can you list the other SIX ways it is possible to make 18 in our 5puzzle challenge?
The 7puzzle Challenge
The playing board of the 7puzzle game is a 7-by-7 grid of 49 different numbers, ranging from 2 up to 84.
The 3rd & 5th rows contain the following fourteen numbers:
6 7 13 16 21 25 36 42 45 50 66 80 81 84
What is double the highest prime number on the list?
. . . can be found when clicking this.