Answer:
The maximum value of N-M will be 792
Step-by-step explanation:
For N - M to be maximum
N must be very large and M must be very small
largest 3 numbers occur in 900's and smallest 3 digit numbers occur in 100's
so we need such an N which starts with 9 and ends with 1 so that on reversing it produces a number starting with 1.
If N = 901 , M will be 109
N - M = 792
This is the largest possible value of N - M
All other values of N-M will give a smaller value than 792.
