By weight/the dozen

[Untaught88]

Hi,

1) Eggs are sold by the dozen.
'The' is used because 'dozen' is countable.

2) Mangoes are sold by weight.
'The' is not used because 'weight' is uncountable. Correct me if I am wrong, please.

 

[jutfrank]

You're wrong on both accounts.

 

[SoothingDave]

"Dozen" is a unit of measure here. Units of measure would use the definite article. It's sold by weight. It's sold by the pound. It's sold by volume. It's sold by the gallon.

 

[probus]

Hi,

1) Eggs are sold by the dozen.
'The' is used because 'dozen' is countable.

2) Mangoes are sold by weight.
'The' is not used because 'weight' is uncountable. Correct me if I am wrong, please.

No. It's the eggs that are countable, not the word dozen. Similarly, it's not the mangoes that are uncountable, but their weight.