What are the type codes for products?
select product_name, product_type_code from products
Can you count the products for each type code?
select product_type_code, count(*) from products group by product_type_code
Which is most common?
select product_type_code from products group by product_type_code order by count(*) desc limit 1
Show the ones with at least two products.
select product_type_code from products group by product_type_code having count(*) >= 2
Show those ones that have products with price higher than 4500 and products with price lower than 3000.
select product_type_code from products where product_price > 4500 intersect select product_type_code from products where product_price < 3000