Why do you add a zero when multiplying two digits by two digits

Three coins are flipped. what is the probability that there will be at least two tails?

Identify the converse of the following conditional: if a point is in the first quadrant, then its coordinates are positive. if the coordinates of a point are not positive, then the point is not in the first quadrant. if the coordinates of a point are positive, then the point is in the first quadrant. if a point is in the first quadrant, then its coordinates are positive. if a point is not in the first quadrant, then the coordinates of the point are not positive.

Extra points! find the missing dimension! need asap