Visual Logic help

[nisivio2]

i am having trouble making a program for visual logic the question is 2-5 Grade Determination is says " Write a program that will input three test scores. the program should determine and display their average. the program should then display the appropriate letter grade based on there average. the letter grade should be determined using a 10 point scale (a=90-100)(b=80-89.999)(c=70-79.999),etc.