Consider a banking database with three tables and primary keys underlined as given below:

Customer(CustomerID, CustomerName, Address, Phone, Email)

Owns(CustomerID, AccountNumber)

Account(AccountNumber, AccountType, Balance)

Write both relational algebra and SQL queries:

a. To display name of all customers who live in “Kathmandu”.

b. To count total number of customers.

c. To find name of those customers who have balance greater than or equal to 100000.

d. To find average balance of each account type.