Here's a short story:

Private schools, also known as independent schools, non-governmental, or nonstate schools, are not administered by local, state or national governments; thus, they retain the right to select their students and are funded in whole or in part by charging their students tuition, rather than relying on mandatory taxation through public (government) funding; at some private schools students may be able to get a scholarship, which makes the cost cheaper, depending on a talent the student may have (e.g. sport scholarship, art scholarship, academic scholarship), financial need, or tax credit scholarships that might be available. 

In the United Kingdom and several other Commonwealth countries including Australia and Canada, the use of the term is generally restricted to primary and secondary educational levels; it is almost never used of universities and other tertiary institutions. Private education in North America covers the whole gamut of educational activity, ranging from pre-school to tertiary level institutions. Annual tuition fees at K-12 schools range from nothing at so called 'tuition-free' schools to more than $45,000 at several New England preparatory schools. (End of story)

Provide your best guess for the following question. Give ONLY the guess, no other words or explanation.

For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>

Question: Why do private school asked for money from their students ?

because they do not take money from the government