Ten small planes are flying at a speed of `150 km//h` in total darkness in an air space that is `20 xx 20 xx 1.5 km^(3)` in volume. You are in one of the planes, flying at random within this space with no way of knowing where the other planes are, On the average about how long a time will elapse between near collision with your plane. Assume for this rough computation that a safety region around the plane can be approximately by a sphere of radius 10 m.

Explanation

To solve the problem, we will follow these steps:

### Step 1: Determine the volume of the airspace
The airspace is given as a rectangular prism with dimensions \(20 \, \text{km} \times 20 \, \text{km} \times 1.5 \, \text{km}\).

\[ \text{Volume} = 20 \times 20 \times 1.5 = 600 \, \text{km}^3 \]
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