Table 2.

Different levels’ settings.

	Time (s)	Grid Size	No. of Slices	Display		Image Level
				Color	Greyscale	Easy	Medium	Hard
Level 1	50	3×3	9	X		X
Level 2	50	3×4	12		X	X
Level 3	50	4×4	16		X		X
Level 4	50	5×4	20		X			X