Explain the relative rates of `RX` with `H_2 O + EtOH` at `25^@ C` as given :
(i) `MeBr (2140)`
(ii) `MeCH_2 Br(171)`
(iii) `Me_2 CHBr (4.99)`
(iv) `Me_3CBr (1010)`
(b) Why is `EtOH` added to water ?

Explanation

To explain the relative rates of the reactions of the given alkyl halides (RX) with water and ethanol at 25°C, we need to analyze each compound based on its structure and the type of reaction mechanism it undergoes.

### Step-by-Step Solution:

1. **Identify the Alkyl Halides:**
- (i) MeBr (Methyl bromide)
- (ii) MeCH2Br (Ethyl bromide)
- (iii) Me2CHBr (Isopropyl bromide)
...