Problems(1)
Two natural numbers, p and q, do not end in zero. The product of any pair, p and q, is a power of 10
(that is, 10,100,1000,10000 , ...). If p>q, the last digit of p–q cannot be<spanclass=′latex−bold′>(A)</span> 1<spanclass=′latex−bold′>(B)</span> 3<spanclass=′latex−bold′>(C)</span> 5<spanclass=′latex−bold′>(D)</span> 7<spanclass=′latex−bold′>(E)</span> 9 Gauss