1) 4 hours OT on a normal working day = 9.375x1.5x4=56.25. Total wages will be RM50+56.25=106.25
2) 4 hours OT on Rest day =9.375x2x4=75.00 Total wages will Rm50x2+75.00=175
3) 4 hours OT on public holiday=9.375x3x4=112.5 Total wages will be RM50x3+112.5=262.5
Please read Sections 60, 60A and 60D of the Employment Act.