The answer is B. Because it says vertical line so it can’t be y. (Y would be a horizontal line.) Then -4 matches the x value of the expression given and if you plot it on a graph -4 passes though the given point.
9/20 is the probability that Bob's password consists of an odd single-digit number followed by a letter and a positive single-digit number
It is given that bob's password consists of a non-negative single-digit number followed by a letter and another non-negative single-digit number (which could be the same as the first one).
P (odd single digit number ) = ( 5 odd single digits / 10 non-negative single digits) = (5/10) = 1/2
P (positive single digit number ) = (9 positive single digits / 10 non-negative single digits) = 9/10
