Exercise 02: Based on LINQ extension methods. [15 marks] Create an Invoice class which includes four properties - a PartNumber ( type int), a PartDescription ( type string), a Quantity of item being purchased (type int) and a Pricel type decimal). Use the following sample data for Invoice class objects: Quantity 7 Part Number 87 24 7 77 39 68 Part Description Electric Sander Power Saw Sledge Hammer Hammer Lawn Mower Screw Driver Jig saw 18 11 76 3 Price 57.98 99.99 21.50 11.99 79.50 6.99 11.00 106 56 21 Perform the following queries on the array of Invoice objects and display the results: a) Use LINQ to select from each Invoice the PartDescription and value of the Invoice ( i.e. Quantity * Price ). Name the calculated column as Invoice Total. Order the results by invoice value in ascending order. [Hint: use let ] b) Part description of the part who has highest quantity. c) Average price of the parts