The reason for the error is that the method signature of the BrewMethod states that it expects five string arguments called power, flavour, lid, s and water.
public void BrewMethod(string power, string flavor, string lid, string s, string water)
However when you call the BrewMethod method from other methods you only call it with one argument.
public void PowerMethod()
{
string power = "on";
Console.WriteLine("Coffee Maker is now on.");
BrewMethod(power); <------ Called with one argument whereas fivearguments are expected
CupMethod(power);
WaterMethod(power);
SizeMethod(power);
}
You must therefore provide the missing arguments to the BrewMethod wherever you call it.