import math
class exo2(object):
    """description of class"""
    def __init__(self, nb1, nb2):
        self.nbq = nb1
        self.nbc = nb2

    def calcul(self):
        chanceWinNbc = 1/self.nbc
        chanceLossNbc = 1- chanceWinNbc
        questionWin = int(round((60*self.nbq) /100))
        questionLoss = self.nbq - questionWin
        total = math.pow(chanceWinNbc,questionWin) + math.pow(chanceLossNbc,questionLoss)

        return total