1. Consider experiments with the following censoring mechanism: A group of n units is observed from time 0; observation stops at the time of the rth failure or at time C, whatever occurs first. Show by direct calculation that the likelihood function is of the form n L = I (t;)i S'(t;+)-8i, i=1 assuming that the units gave failure times which are i.i.d. with survivor function S(t) and p.d.f. f(t). (Hint: first define t and S.)