Question

I forgot the last digit of a 7-digit telephone number. If 1 randomly dial the final 3 digits after correctly dialing the first four, then what is the chance of dialing the correct number?

A) 1/999 B) 1/1001 C) 1/1000 D) 4/1000

Answer 1

1/10*10*10=1/1000

is the correct probability