import java.math.*;
import java.text.*;

class Main {
  static double result;
  static double[] prob;
  static double[] flies;
  static int leaves;

   //static double[][] DP; // temp results

    public static void main(String[] args) {
        // Uncomment this line if you want to read from a file
        In.open("public/sample.in");

        int t = In.readInt();
        for (int i = 0; i < t; i++) {
            testCase();
        }

        // Uncomment this line if you want to read from a file
        //In.close();
    }

    public static void testCase() {
        // Input using In.java class
        int leaves = In.readInt();
        //Out.print(leaves + " ");
        int startleaf = In.readInt();
        //Out.print(startleaf+ " ");
        int jumps = In.readInt();
        //Out.println(jumps);

        flies = new double[leaves+1];
        prob = new double[leaves+1];
        //save values of probs for each leaf :
        for(int i = 0; i<leaves; i++){
          flies[i] = In.readInt();
          //Out.print(flies[i] + " ");
        }
       // Out.println();
        for(int i = 0; i<leaves; i++){
          prob[i] = In.readDouble();
          //Out.print(prob[i] + " ");
        }
        //Out.println();

        //DP = new double[leaves+1][jumps+1];
      //initial number of flies eaten
      /*for(int i = 0; i<=leaves; i++){
        for(int j = 0; j<=jumps; j++){
          DP[i][j] = -1.0;// DP[i][j] : number of flies eaten, with j jumps, starting at leaf i
        }
      }*/

        DecimalFormat df = new DecimalFormat("0.0####");
        df.setRoundingMode(RoundingMode.HALF_DOWN);
        System.out.println(df.format(calcul(startleaf, jumps)));
    }

    static double calcul(int startleaf, int jumps){
      /*if (DP[startleaf][jumps] != -1.0) {//we already have the result
        return DP[startleaf][jumps];
      }*/
      if (jumps == 0){
        if(startleaf>=0 && startleaf<=leaves){
        return flies[startleaf];
        }
      }
      /*if(startleaf<0 || startleaf>leaves){
      }

      double sum = 0.0;
      double left = 0.0;
      double right = 0.0;
      for(int i = 0; i<jumps; i++){//nombre d'additions
        if(startleaf==0){
          if(1-prob[startleaf] == 1.0){//si la prob d'aller à droite ==1
            sum *= (1-prob[startleaf])*calcul(startleaf+1, jumps-1);
            return flies[startleaf] + sum;
          }
          else{
            if(prob[startleaf] == 1.0){
            return flies[startleaf];
          }
          }
        }
        else if(startleaf==leaves){
          if(prob[startleaf] == 1.0){
          sum *= prob[startleaf]*calcul(startleaf-1, jumps-1);
          return flies[startleaf] + sum;
          }
          else if(prob[startleaf] == 0.0){
            return flies[startleaf];
          }
        }
        else{
        left *= prob[startleaf]*calcul(startleaf-1, jumps-1);
        right *= (1-prob[startleaf])*calcul(startleaf+1, jumps-1);
        return flies[startleaf] + left + right;
        //sum += prob[startleaf]*flies[startleaf-1] + (1-prob[startleaf])*flies[startleaf+1];
        }
      }
      return sum;*/

      if(startleaf == leaves){
         DP[startleaf][jumps] = prob[startleaf]*flies[startleaf-1];
         return flies[startleaf] + DP[startleaf][jumps];
      }
      else if(startleaf == 0){
        DP[startleaf][jumps] = flies[startleaf] + (1-prob[startleaf])*flies[startleaf+1];
      }
      else{
      DP[startleaf][jumps] = flies[startleaf] + prob[startleaf]*calcul(startleaf-1, jumps-1) + (1-prob[jumps])*calcul(startleaf, jumps-1);

      //DP[startleaf][jumps] = prob[startleaf]*flies[startleaf-1] + (1-prob[startleaf])*flies[startleaf+1];
      }
      return DP[startleaf][jumps];
    }


}