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Option 4 : 27 ∶ 48 ∶ 87

Area which is painted with blue colour = 6 × 6 × 6 = 216 cm3

When the cube is cut into cubes of side 1 cm,

⇒ Number of cubes with only one side painted with blue colour = 6 × 4 × 4 = 96

⇒ Number of cubes with only two sides painted with blue colour = 12 × 4 = 48

⇒ Number of cubes with only three sides painted with blue colour = 8

⇒ Number of cubes with only no side painted with blue colour = 216 - 96 - 48 - 8 = 64

⇒ Area which is painted with green colour = 96 × 1 × 5 + 48 × 1 × 4 + 8 × 1 × 3 = 480 + 192 + 24 = 696

⇒ Area which is painted with red colour = 64 × 1 × 6 = 384

∴ Ratio of blue painted, red painted and green painted area = 216 ∶ 384 ∶ 696 = 27 ∶ 48 ∶ 87
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