Geometry

Question Analysis:
This question involves calculating the surface area of four identical cubes stacked vertically.
The main focus is on accounting for the hidden surfaces where cubes connect.

Key Concept Explanation:
When cubes stack vertically:
Each connection hides 2 faces
Total surface area = Combined individual surface areas - 2 × contact areas per connection
For 4 cubes there are 3 connections → 6 hidden faces

Step-by-Step Solution:
Single cube surface area: 6 × (5×5) = 150 cm²
Three separate cubes: 4 × 150 = 600 cm²
Hidden surfaces: 6 faces × (5×5) = 150 cm²
Total ...