いけない in this sentence and V-て+noun


I have searched and read articles and questions available regarding いけない and i
do understand that it means that something cannot be done (you mustn't...).  
But i'm a bit unsure about it's meaning in this sentence :

> あのホテルは遠いですから、歩いて20分では行けないでしょう。  
>

Roughly i translate it as

> since that hotel is far, it seems that 20minutes walking there is not enough
> time.

  
I'm confused about what 歩いて20ぷん means : v-て + noun?  
And いけない is must not do, if we use that literal meaning, it becomes we must
not walk 20 minutes... So what is the meaning of いけない in here?




The 行けない is the negative potential form of the verb 行く.  
(「行く」= "go", 「行ける」= "can go", and 「行けない」= "can't go")

The 歩いて here means "on foot", "by walking".

> 歩いて20分では行けない

Think of it as the negative form of 「(ホテルまで)歩いて(20分で)行ける」, "can go (to the
hotel) (in 20 minutes) on foot."

> 歩いて20分では行けないでしょう。

(Lit.) "You won't be able to go/get (there/to the hotel) in 20 minutes on
foot."




The 行けない is the negative potential form of the verb 行く.  
(「行く」= "go", 「行ける」= "can go", and 「行けない」= "can't go")

The 歩いて here means "on foot", "by walking".

> 歩いて20分では行けない

Think of it as the negative form of 「(ホテルまで)歩いて(20分で)行ける」, "can go (to the
hotel) (in 20 minutes) on foot."

> 歩いて20分では行けないでしょう。

(Lit.) "You won't be able to go/get (there/to the hotel) in 20 minutes on
foot."

