from typing import Sequence


def progress_rate (x: Sequence[float], v: Sequence[float], k: float) -> float:
    """ Calculates progress rate for single reaction represented by inputs.

    Args:
        x: Concentration vector.
        v: Stoichiometric coefficients of reactants.
        k: Forward reaction rate coefficient.

    Notes:
        Raises ValueError if sequences x and v are not the same length.

    Returns:
        Reaction progress rate.

    Examples:
    >>> progress_rate([1.0, 2.0, 3.0], [2.0, 1.0, 1.0], 10)
    60.0
    """
    if len(x) != len(v):
        raise ValueError('x and v must be same length.')

    result = 1
    for i, x_i in enumerate(x):
        result *= pow(x_i, v[i])
    return k * result