def flesch_kincaid_grade_level(word_count, syllable_count):
    """Given a number of words and number of syllables in a sentence, computes the
    flesch kincaid grade level.

    Keyword arguments:
    word_count -- number of words in the sentence
    syllable_count -- number of syllables in the sentence
    """
    return 0.39 * word_count + 11.8 * syllable_count / word_count - 15.59