At a certain temperature 6% molecules of a gas have speed `2 m//s`, 9% have speed `3 m//s`, 30% have speed `9 m//s`, 28% have speed `11 m//s`, 20% have speed `13 m//s` and 7% have speed `18 m//s`. Calculate `U_(mp), U_(av)` and `U_(rms)` at that temperature.

Explanation

To solve the problem, we need to calculate the most probable speed (U_mp), average speed (U_av), and root mean square speed (U_rms) of the gas molecules based on the given percentage distribution of their speeds.

### Step-by-Step Solution:

1. **Identify the Given Data:**
- 6% of molecules have speed = 2 m/s
- 9% of molecules have speed = 3 m/s
- 30% of molecules have speed = 9 m/s
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