The idea that intelligence can be directly increased by effort is referred to as theory.

Incremental theory

Explanation:

The incremental theory of intelligence proposes that intelligence and ability are traits that can be malleable and improved through effort and hard work. This means that every time you perform an activity, you learn a little bit more, and these experiences allow you to increase your intelligence. Therefore, people who subscribe to this mindset usually believe that mastery is possible even in an area where they are initially very unskilled.

what is the tax base for the sales tax?

it should be (usually ) 6%