You can use "tanto" for almost everything but when you use "tanta" it has to be a word that ends with "a" or you can guide by the words that start with "la" on a sentence.
For example:tantas niñas, tantas mesas, tantas casas.
All those words start with "la":las niñas, las mesas, las casas.
The answer is la.. I speak Spanish
Answer:
The air conditioner makes noise when it is off
