Here's some guidelines for Question 1 Activity diagram:

-use 3 partitions

-there is no decision node

-use a fork & join node

-add the Object "Transaction"

-add the state to the object using the correct tool in Astah

Sales Purchase

Using an activity diagram, represent the actions of a sales purchase, based on the following description: Customers drive their vehicle to a gas pump to purchase gas. Attendants pump the gas into the vehicle. The transaction opens when the attendant lifts the gas nozzle. When the attendant finishes pumping gas and replaces the nozzle, a total is sent to the cashier.

Customers must pay for the gas inside the store. At the same time the attendant is pumping gas, the customer can shop for items inside the store. Once the customer is finished shopping and the cashier has received the total from the gas pump, the customer can pay for the transaction. After the cashier accepts payment, the transaction is closed.