Which is the only 2-digit number to have exactly seven factors?
. . . and an additional challenge for the number puzzle enthusiast – which is the only 3-digit number to have exactly seven factors?
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 4th & 5th rows of the playing board contain the following fourteen numbers:
3 6 7 10 16 21 32 35 44 50 54 60 81 84
What is the sum of the two square numbers?
. . . can be found when clicking this.