import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Iterator;
import java.io.BufferedWriter;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.util.Comparator;
import java.util.NoSuchElementException;
import java.io.InputStream;
/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        C solver = new C();
        int testCount = Integer.parseInt(in.next());
        for (int i = 1; i <= testCount; i++)
            solver.solve(i, in, out);
        out.close();
    }

    static class C {
        int DIV = 10 * 1000 * 1000;
        double[][] mem;
        int[] prefixPre;

        double dp(int travelIndex, boolean prevFound, Integer[] perm, int[] saved, int[] x) {
            if (travelIndex == perm.length) return 0;
            if (mem[travelIndex][prevFound ? 1 : 0] > -1) return mem[travelIndex][prevFound ? 1 : 0];
            int idx = perm[travelIndex];
            double res = prevFound ? saved[idx] : 0;
            if (prevFound) {
                res += dp(travelIndex + 1, true, perm, saved, x);
            } else {
                int prefix = prefixPre[travelIndex];
                double probFind = (DIV - prefix == 0) ? 0 : ((double) x[idx] / (DIV - prefix));
                double savedIfFound = dp(travelIndex + 1, true, perm, saved, x);
                double savedIfNotFound = dp(travelIndex + 1, false, perm, saved, x);
                res += probFind * savedIfFound;
                res += (1 - probFind) * savedIfNotFound;
            }
            return mem[travelIndex][prevFound ? 1 : 0] = res;
        }

        public void solve(int testNumber, InputReader in, OutputWriter out) {
            int n = in.readInt();
            mem = new double[n][2];
            ArrayUtils.fill(mem, -2);
            int[] a = new int[n], b = new int[n], x = new int[n];
            IOUtils.readIntArrays(in, a, b, x);
            int[] saved = new int[n];
            for (int i = 0; i < saved.length; i++) saved[i] = a[i] - b[i];
            Integer[] perm = new Integer[n];
            for (int i = 0; i < perm.length; i++) perm[i] = i;
            Arrays.sort(perm, new Comparator<Integer>() {
                public int compare(Integer o1, Integer o2) {
                    double val1 = (double) saved[o1] / x[o1];
                    double val2 = (double) saved[o2] / x[o2];
                    return Double.compare(val1, val2);
                }
            });
            prefixPre = new int[n + 1];
            for (int i = 1; i < prefixPre.length; i++) {
                prefixPre[i] = prefixPre[i - 1] + x[perm[i - 1]];
            }
            double savings = dp(0, false, perm, saved, x);
            out.printLine(ArrayUtils.sumArray(a) - savings);
        }
    }
    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void print(Object... objects) {
            for (int i = 0; i < objects.length; i++) {
                if (i != 0) {
                    writer.print(' ');
                }
                writer.print(objects[i]);
            }
        }

        public void printLine(Object... objects) {
            print(objects);
            writer.println();
        }

        public void close() {
            writer.close();
        }
    }
    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public int readInt() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public String readString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                }
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next() {
            return readString();
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);
        }
    }
    static class ArrayUtils {
        public static void fill(double[][] array, double value) {
            for (double[] row : array) {
                Arrays.fill(row, value);
            }
        }

        public static long sumArray(int[] array) {
            return new IntArray(array).sum();
        }
    }
    static interface IntStream extends Iterable<Integer>, Comparable<IntStream> {
        public IntIterator intIterator();
        default public Iterator<Integer> iterator() {
            return new Iterator<Integer>() {
                private IntIterator it = intIterator();

                public boolean hasNext() {
                    return it.isValid();
                }

                public Integer next() {
                    int result = it.value();
                    it.advance();
                    return result;
                }
            };
        }
        default public int compareTo(IntStream c) {
            IntIterator it = intIterator();
            IntIterator jt = c.intIterator();
            while (it.isValid() && jt.isValid()) {
                int i = it.value();
                int j = jt.value();
                if (i < j) {
                    return -1;
                } else if (i > j) {
                    return 1;
                }
                it.advance();
                jt.advance();
            }
            if (it.isValid()) {
                return 1;
            }
            if (jt.isValid()) {
                return -1;
            }
            return 0;
        }
        default public long sum() {
            long result = 0;
            for (IntIterator it = intIterator(); it.isValid(); it.advance()) {
                result += it.value();
            }
            return result;
        }
    }
    static interface IntCollection extends IntStream {
        public int size();
    }
    static class IOUtils {
        public static void readIntArrays(InputReader in, int[]... arrays) {
            for (int i = 0; i < arrays[0].length; i++) {
                for (int j = 0; j < arrays.length; j++) {
                    arrays[j][i] = in.readInt();
                }
            }
        }
    }
    static abstract class IntAbstractStream implements IntStream {
        public String toString() {
            StringBuilder builder = new StringBuilder();
            boolean first = true;
            for (IntIterator it = intIterator(); it.isValid(); it.advance()) {
                if (first) {
                    first = false;
                } else {
                    builder.append(' ');
                }
                builder.append(it.value());
            }
            return builder.toString();
        }

        public boolean equals(Object o) {
            if (!(o instanceof IntStream)) {
                return false;
            }
            IntStream c = (IntStream) o;
            IntIterator it = intIterator();
            IntIterator jt = c.intIterator();
            while (it.isValid() && jt.isValid()) {
                if (it.value() != jt.value()) {
                    return false;
                }
                it.advance();
                jt.advance();
            }
            return !it.isValid() && !jt.isValid();
        }

        public int hashCode() {
            int result = 0;
            for (IntIterator it = intIterator(); it.isValid(); it.advance()) {
                result *= 31;
                result += it.value();
            }
            return result;
        }
    }
    static interface IntList extends IntReversableCollection {
        public abstract int get(int index);
        public abstract void removeAt(int index);
        default public IntIterator intIterator() {
            return new IntIterator() {
                private int at;
                private boolean removed;

                public int value() {
                    if (removed) {
                        throw new IllegalStateException();
                    }
                    return get(at);
                }

                public boolean advance() {
                    at++;
                    removed = false;
                    return isValid();
                }

                public boolean isValid() {
                    return !removed && at < size();
                }

                public void remove() {
                    removeAt(at);
                    at--;
                    removed = true;
                }
            };
        }
    }
    static interface IntIterator {
        public int value() throws NoSuchElementException;
        public boolean advance();
        public boolean isValid();
    }
    static interface IntReversableCollection extends IntCollection {
    }
    static class IntArray extends IntAbstractStream implements IntList {
        private int[] data;

        public IntArray(int[] arr) {
            data = arr;
        }

        public int size() {
            return data.length;
        }

        public int get(int at) {
            return data[at];
        }

        public void removeAt(int index) {
            throw new UnsupportedOperationException();
        }
    }
}