Answer:
See explanation
Explanation:
The complete question is
Write a SELECT statement that returns the same result set as this SELECT statement, but don't use a
join. Instead, use a subquery in a WHERE clause that uses the IN keyword.
SELECT DISTINCT category_name
FROM categories c JOIN products p
ON c.category_id = p.category_id
ORDER BY category_name
The join clause gives us all the registers of both tables, for which the category_id of categories coincides to the category_id in the table products. That is, we can first select the distinct category_id's from products and the see the categories from categories table, whose id is in that list. That means writing the following query:
Select distinct category_name
from categories c
where c.category_id in (
select distinct p.category_id
from products p)
order by category_name
Answer:
The percentage of the remaining alloy would become solid is 20%
Explanation:
Melting point of Cu = 1085°C
Melting point of Ni = 1455°C
At 1200°C, there is a 30% liquid and 70% solid, the weight percentage of Ni in alloy is the same that percentage of solid, then, that weight percentage is 70%.
The Ni-Cu alloy with 60% Ni and 40% Cu, and if we have the temperature of alloy > temperature of Ni > temperature of Cu, we have the follow:
60% Ni (liquid) and 40% Cu (liquid) at temperature of alloy
At solid phase with a temperature of alloy and 50% solid Cu and 50% liquid Ni, we have the follow:
40% Cu + 10% Ni in liquid phase and 50% of Ni is in solid phase.
The percentage of remaining alloy in solid is equal to
Solid = (10/50) * 100 = 20%
