This paper gives sharp bounds for the joint survival function G(ti, t2,. . . ,t.) -X1 > tb, X2 > t2,. . . ,Xr > tr), and for the marginal survival functions Sjt) = X > t), j = 1,2,.. . ,r, when the sub-survival functions S;(t)= AX >,=mn=1,2.rXk) are fixed. Theorem 1 gives the bounds for r = 2, and Theorem 2 gives the bounds for general r. Theorem 3 applies the result to the competing risks problem, and presents empirical bounds based on the observations. Finally, an example illustrates the bounds.