In the following grid, a number in any square above the bottom row is obtained by adding the numbers connected to it from the row below. For example, the 5 in
the second last row is obtained by adding the numbers connected to it in the row
below. 2 and 3. The numbers filter up until reaching the final square containing
23. That is, the number in the top square is two times the unknown number in
the bottom row
Determine the value of
2x
5
2
3
C