Question

Find the number of two-digit numbers which increase their value by 18 if their digits are reversed​

Answer 1

Answer:

This can be calculated easily. As any two digit number can be written in the following form: N = 10x + y If we reverse the number now, it would become: N^ prime =10y+x So if we subtract one from the other, we should obtain 18 ( as mentioned in the question ). N - N = 18 =>x-y=2 Thus, any number whose digits differ by two would be an aswer to the question. The only numbers which satisfy this are : 35, 46, 57, 68, 79 But this would not be true for any 3 or more digit number