We present the maxima and minima of a class of overall survival functions for the case in which the marginal distributions are fixed. The theory of copulas, especially the Frechet-Hoeffding upper and lower bounds, plays a crucial role here. We also present an application to the education system for the case in which the marginal distributions obey the Weibull distribution. In particular, we discuss the minimum number of new employees a company should hire per old employee in order to transmit technology in Japan. Our result can be applied to any country where the relevant social data is available.