about ten to one
`` The ray crews are on duty , I presume ? '' `` Yes . But I doubt that the rays will be of much assistance to us . Particularly if these are stony meteorites -- and as you know , the odds are about ten to one against their being of ferrous composition . The rays , deducting the losses due to the utter lack of a conducting medium , will be insufficient protection . They will help , of course . The iron meteorites they will take care of effectively , but the conglomerate nature of the stony meteorites does not make them particularly susceptible to the disintegrating rays .