Geometry

Question Analysis:
This question involves calculating the surface area of three 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 (top of lower cube and bottom of upper cube)
Total surface area = Combined individual surface areas - 2 × contact areas per connection
For 3 cubes there are 2 connections → 4 hidden faces

Step-by-Step Solution:
Single cube surface area: 6 × (5×5) = 150 cm²
Three separate cubes: 3 × 150 = 450 cm²
Hidden surfaces: 4 faces × (5×5...