Need a help in • Geometry •......?

Refer to the diagram below to cut slabs from the cubic block:
Size of the cubic block = 1 × 1 × 1 m³ = 100 × 100 × 100 cm³
Distance between two red lines = 20 cm
Distance between two blue lines = 5 cm

Total number of slabs that can be cut = (100/20) × (100 × 20) × (100/5) = 500
Number of slabs including the fracture = 5 × (100/5) = 100
Number of slabs avoiding the fracture = 500 - 100 = 400

The answer: 3. 400

400