During the first week of July 2006, the workman Mr. X manufactured 300 articles. He received wages for a guaranteed 48 hours week at the rate of 4 per hour. The estimated time to produce one article is 10 minutes and under incentive scheme the time allowed is increased by 20%. Calculate his gross wages and effective hourly rate according to : (i) Piece rate with a guaranteed weekly wages; (ii) Rowan premium bonus; and (iii) Halsey premium bonus