diff --git a/ideas/split-loop-with-lambda/exercise3/.gitignore b/ideas/split-loop-with-lambda/exercise3/.gitignore
new file mode 100644
index 0000000..ac8d21b
--- /dev/null
+++ b/ideas/split-loop-with-lambda/exercise3/.gitignore
@@ -0,0 +1,3 @@
+bin/
+obj/
+*.user
diff --git a/ideas/split-loop-with-lambda/exercise3/README.md b/ideas/split-loop-with-lambda/exercise3/README.md
index 546b5a4..a39bed8 100644
--- a/ideas/split-loop-with-lambda/exercise3/README.md
+++ b/ideas/split-loop-with-lambda/exercise3/README.md
@@ -5,7 +5,8 @@ A third, minimal example in the same kata theme: the sellers exist
 `Buyers` computes a buyer's shopping-list total, and `PriceList` stands for an
 external pricing service (it adds random surge pricing, so the test is flaky).
 
-Written in **C#** (MSTest, .NET 7 — same setup as the kata's `csharp/` folder).
+Written in **C#** (MSTest, .NET 10; verified with `dotnet test` on SDK
+10.0.4xx — pristine test is flaky by design, solution is deterministic).
 Run with `dotnet test test/BuyersTests.csproj`.
 
 Contents:
@@ -33,8 +34,9 @@ Next-time arc: marketing adds surge discounts, `PriceList` grows
 `DiscountFor(...)` — two methods to stub → extract a role interface
 (`IPricing`) instead of two lambdas. See the demo script's closing note.
 
-## Not verified by a build
+## Verified
 
-This exercise was authored without a local .NET SDK (structurally mirrored from
-the kata's `csharp/` project files). Run `dotnet test test/BuyersTests.csproj`
-once on a machine with the SDK before facilitating.
+Built and run with `dotnet test` (SDK 10.0.4xx): solution green deterministically,
+pristine test flaky (failed 2 of 3 runs, passed 1 — both surges rolled 0).
+MSTest bumped to 3.6.4 (kata ships 2.1.1, whose transitive Newtonsoft.Json trips
+a NU1903 vulnerability warning).
diff --git a/ideas/split-loop-with-lambda/exercise3/csharp/global.json b/ideas/split-loop-with-lambda/exercise3/csharp/global.json
index 37704f0..6e016cf 100644
--- a/ideas/split-loop-with-lambda/exercise3/csharp/global.json
+++ b/ideas/split-loop-with-lambda/exercise3/csharp/global.json
@@ -1,7 +1,7 @@
 {
   "sdk": {
-    "version": "7.0.0",
-    "rollForward": "latestMajor",
+    "version": "10.0.0",
+    "rollForward": "latestFeature",
     "allowPrerelease": true
   }
 }
diff --git a/ideas/split-loop-with-lambda/exercise3/csharp/src/Buyers.csproj b/ideas/split-loop-with-lambda/exercise3/csharp/src/Buyers.csproj
index 8268829..4340f62 100644
--- a/ideas/split-loop-with-lambda/exercise3/csharp/src/Buyers.csproj
+++ b/ideas/split-loop-with-lambda/exercise3/csharp/src/Buyers.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
 
 </Project>
diff --git a/ideas/split-loop-with-lambda/exercise3/csharp/test/BuyersTests.csproj b/ideas/split-loop-with-lambda/exercise3/csharp/test/BuyersTests.csproj
index 09707bf..f679db0 100644
--- a/ideas/split-loop-with-lambda/exercise3/csharp/test/BuyersTests.csproj
+++ b/ideas/split-loop-with-lambda/exercise3/csharp/test/BuyersTests.csproj
@@ -1,14 +1,14 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.1" />
-    <PackageReference Include="MSTest.TestAdapter" Version="2.1.1" />
-    <PackageReference Include="MSTest.TestFramework" Version="2.1.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
+    <PackageReference Include="MSTest.TestAdapter" Version="3.6.4" />
+    <PackageReference Include="MSTest.TestFramework" Version="3.6.4" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/ideas/split-loop-with-lambda/exercise3/solution/global.json b/ideas/split-loop-with-lambda/exercise3/solution/global.json
index 37704f0..6e016cf 100644
--- a/ideas/split-loop-with-lambda/exercise3/solution/global.json
+++ b/ideas/split-loop-with-lambda/exercise3/solution/global.json
@@ -1,7 +1,7 @@
 {
   "sdk": {
-    "version": "7.0.0",
-    "rollForward": "latestMajor",
+    "version": "10.0.0",
+    "rollForward": "latestFeature",
     "allowPrerelease": true
   }
 }
diff --git a/ideas/split-loop-with-lambda/exercise3/solution/src/Buyers.csproj b/ideas/split-loop-with-lambda/exercise3/solution/src/Buyers.csproj
index 8268829..4340f62 100644
--- a/ideas/split-loop-with-lambda/exercise3/solution/src/Buyers.csproj
+++ b/ideas/split-loop-with-lambda/exercise3/solution/src/Buyers.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
 
 </Project>
diff --git a/ideas/split-loop-with-lambda/exercise3/solution/test/BuyersTests.csproj b/ideas/split-loop-with-lambda/exercise3/solution/test/BuyersTests.csproj
index 09707bf..f679db0 100644
--- a/ideas/split-loop-with-lambda/exercise3/solution/test/BuyersTests.csproj
+++ b/ideas/split-loop-with-lambda/exercise3/solution/test/BuyersTests.csproj
@@ -1,14 +1,14 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.1" />
-    <PackageReference Include="MSTest.TestAdapter" Version="2.1.1" />
-    <PackageReference Include="MSTest.TestFramework" Version="2.1.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
+    <PackageReference Include="MSTest.TestAdapter" Version="3.6.4" />
+    <PackageReference Include="MSTest.TestFramework" Version="3.6.4" />
   </ItemGroup>
 
   <ItemGroup>