Then calculate the infeasible situation:
Number of cases with odd mantissa: 5*9! /(6! *3! )*3! =2520;
The first digit is "0" and the last digit is even (including odd): 4*8! /(2! *6! )*2! =224;
So the answer is: (5040-224-2520)/5040 = 2296/5040 = 41/90.
The challenge is simple
Suning
The famous Russian chemist Leenders gave his son a chemistry problem. The result was wrong, not because it was difficult, but becau