i) y-axis coordinates are given by (0,y), x-coordinate is always zero for the point which is lying on y-axis, so statement is True.
ii) As explained above for a point to be on y-axis, its x-coordinate must be zero, so the statement is false. Correct statement: A point whose y coordinate is zero and x-coordinate is 5 will lie on x-axis.
iii) Origin is the point where both x and y coordinates are zero, so statement is True.