Someone plz answer these 3 different questions

1.The sales tax on a new Fridge that costs $1800 was $166.50 What is the Sales tax in Percent?


2.The Alvarez's lived in a hours that had area of 1575 square foot. Now they moved to a bigger house that has area of 2100 square foot. What it the percent increase in square foot?


3.The Alvarez's lived in a hours that had area of 1575 square foot. Now they moved to a bigger house that has area of 2100 square foot. What it the percent increase in square foot?