Formatting a double to two decimal places

Question

I have been trying to make the answer this prints out to be to two decimal places. All the math involved has to stay at that format of two decimal places. I have tried a few

Answer 1

    double d =  3.1493745;
    string s = $"{d:0.00}"; // or $"{d:#.##}"
    Console.WriteLine(s); // Displays 3.15