# A problem by niiyle dick

Victoria, my good friend, once said me that her brother is very nice in algebra. I gave her bro nick 101 tickets. Each of them contained numbers from 1 to 101. Now i told Nick ,m & n are positive real number [not fractional] such that F(m,n):the probability of [{(7)^m}+{(7)^n}] /(5)=natural number;(m,n) belongs to [1,101]. I asked what is the difference between F{(m+1},(n+1)} & F(m,n) ?He answered correctly. What was his answer?