C is a sentence fragment it does not have a verb
Your question wasn't very clear, but I think I understand what you want. Additionally, you should really state what language you're working with. Here it is in C#, and shouldn't be too much of a hassle to translate in to other languages.
Console.Write("Enter payment: ");
float payment;
if (float.TryParse(Console.ReadLine(), out payment))
Console.WriteLine((Math.Floor(payment * 100) / 100) * 0.15, + " at 15% tip.");
else
Console.WriteLine("Invalid input.");
Answer:
With modeling and simulation, we model the system and then test the system to gather test predictions.
Explanation:
You would have to test the system in order to see if it's working right and everything is all good with the system.
I hope this helped. I am sorry if you get this wrong.
Answer:
c for the first one and d for the secound one
Explanation:
