IKMC 2027 - Grades 7-8 - Self-study SET 10 - Thematic Batch 3 Question 29

Figures B1,B2,B3,B4,... follow the shown pattern of joined unit cubes. Their surface-area-to-volume ratios begin 6/1=6,10/2=5,14/3=4.666... . Which figure has ratio 4.1?