added solution with tariff options as enum and map

src/main/java/com/pfefferminzia/petinsurance/tariffs/AgeTariff.java

@@ -0,0 +1,27 @@
+package com.pfefferminzia.petinsurance.tariffs;
+
+import java.math.BigDecimal;
+
+public enum AgeTariff {
+    UP_TO_TWO(2, new BigDecimal("0.2")), UP_TO_FIVE(5, new BigDecimal("0.25")), UP_TO_SEVEN(7,
+            new BigDecimal("0.28")), OVER_SEVEN(Integer.MAX_VALUE, new BigDecimal("0.3"));
+
+    private final int maxAge;
+
+    private final BigDecimal factor;
+
+    private AgeTariff(int maxAge, BigDecimal factor) {
+        this.maxAge = maxAge;
+        this.factor = factor;
+    }
+
+    public static BigDecimal getFactorForAge(int age) {
+        for (AgeTariff rate : values()) {
+            if (age <= rate.maxAge) {
+                return rate.factor;
+            }
+        }
+        throw new AssertionError("Unexpected age: " + age);
+    }
+
+}