diff --git a/modules/11_cpp17/src/variant.cpp b/modules/11_cpp17/src/variant.cpp
index a926a71..48c4217 100644
--- a/modules/11_cpp17/src/variant.cpp
+++ b/modules/11_cpp17/src/variant.cpp
@@ -3,18 +3,32 @@
 namespace cpp17 {
 
 auto variant_to_string(const Value& value) -> std::string {
-    (void)value;
+    if (std::holds_alternative<int>(value)) {
+        return "int:" + std::to_string(std::get<int>(value));
+    }
+    if (std::holds_alternative<double>(value)) {
+        return "double:" + std::to_string(std::get<double>(value));
+    }
+    if (std::holds_alternative<std::string>(value)) {
+        return "string:" +std::get<std::string>(value);
+    }
     return {};
 }
 
 auto sum_numeric_variants(const std::vector<Value>& values) -> double {
-    (void)values;
-    return 0.0;
+    auto sum = 0.0;
+    for (const auto& value : values) {
+        if (std::holds_alternative<int>(value)) {
+            sum += static_cast<double>(std::get<int>(value));
+        } else if (std::holds_alternative<double>(value)) {
+            sum += std::get<double>(value);
+        }
+    }
+    return sum;
 }
 
 auto is_string(const Value& value) -> bool {
-    (void)value;
-    return false;
+    return std::holds_alternative<std::string>(value);
 }
 
 }  // namespace cpp17