If the two digit integers M. and N are positive and have the same digits, but in reverse order, which of the following CANNOT be the sum of M and N?
সমাধান
সঠিক উত্তর: Option A
M=10x+y N=10y+x M+N=11x+11y=11(x+y) In other words the answer is a multiple of 11. Now the question becomes " which of the following is NOT a multiple of 11?" answer----->181----->choice A