Section $5-$SQL $(6$ points$)$

Consider the following college database:

College $($c$-$code, c$\_$name$)$

Instructor $($i$-$code, name, age, salary, ccode,$)$

ccode is a FK that references c$-$code $($PK$)$ in College.

Write the SELECT statements to answer the following queries.

List the name of the instructors with an age less than or equal to $50.$

Retrieve the instructor name, age, and college name of all instructors.

Retrieve a list of each college along with the number of instructors who receive

a salary above $15000.$