If two poles 20′′ and 80′′ high are 100′′ apart, then the height of the intersection of the lines joining the top of each pole to the foot of the opposite pole is:
<spanclass=′latex−bold′>(A)</span>50′′<spanclass=′latex−bold′>(B)</span>40′′<spanclass=′latex−bold′>(C)</span>16′′<spanclass=′latex−bold′>(D)</span>60′′<spanclass=′latex−bold′>(E)</span>none of these