Laboratory Exercise: 1. Write a PHP code that will manipulate the number of pieces and the amount of an item purchased by the customer. Assume any value of your choice. Compute and output the Total Cost. Example: The number of pieces: The amount of an item: The total cost: 2. Write a PHP code that will manipulate Midterm and Final Mark. Assume any value of your choice. Compute and output the Total Marks by adding the 40% of Midterm and 60% of Final Marks. 3. ABC Company decided to increase the salary of their employees based on the number of years in service. Write a PHP code that will assume the current salary of an employee. Compute and output the new salary from the increased given by the company. Number of years in Service Percent of increase from employee's current salary More than 10 years 30 percent 5 years to 10 years 20 percent Less than 5 years 10 percent 3. Write PHP code that will manipulate any temperature in Celsius. Then, print its equivalent Fahrenheit temperature. F=C 1.8 +32