Why is a mixed economy not considered a major economic system along with free enterprise and socialism?

Mixed economy is not considered a major economic system along with free enterprise and socialism because the features of these economy are exactly the same with some of the features of free enterprise and socialism. Basically, this type of economic system is just a combination of the features of the free enterprise and socialism. 

b) $7000

Explanation:

College cost

Tuition & fees=$26,000

Room & board=$12,500

Total=$38,500

Financial aid package

Grants& scholarship=$18,500

Work study=$8500

Total=$27,000

Balance=Total college cost- Total financial aid

=$38,500-$27,000

=$11,500

Jorge needs $11,500 to balance his cost

Jorge parents can contribute$4,500 each year

Therefore,

$11,500-$4,500

=$7,000

Jorge needs $7,000 more from his savings or loan to cover his college cost