Added first code.

Signed-off-by: Naoriel Sa' Rocí <naoriel@sa-roci.de>

Models/Question.cs

@@ -0,0 +1,35 @@
+using System;
+
+namespace EinmaleinsTrainer.Models;
+
+public class Question : IEquatable<Question>
+{
+    public int A { get; set; }
+    public int B { get; set; }
+
+    public int CorrectAnswer => A * B;
+
+    public bool Equals(Question? other)
+    {
+        if (other is null) return false;
+
+        return A == other.A &&
+               B == other.B;
+    }
+
+    public override bool Equals(object? obj)
+    {
+        return Equals(obj as Question);
+    }
+
+    public override int GetHashCode()
+    {
+        return HashCode.Combine(A, B);
+    }
+
+    public override string ToString()
+    {
+        return $"{A} x {B}";
+    }
+}
+

Models/QuizModel.cs

@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+
+namespace EinmaleinsTrainer.Models;
+
+public class QuizModel
+{
+    public List<Question> Questions { get; set; } = [];
+    public bool UseTimer { get; set; }
+    public int Seconds { get; set; } = 10;
+}

Models/ResultModel.cs

@@ -0,0 +1,9 @@
+using System;
+namespace EinmaleinsTrainer.Models;
+
+public class ResultModel
+{
+    public int Score { get; set; } = 0;
+    public int Total { get; set; } = 0;
+    public TimeSpan? TimeRequired = null;
+}