Number of regular hours during 4 weeks = 8 x 5 x 4 = 160
Amount paid for regular working hours = 160 x 5 = ₹ 800
Balance left = (920 - 800) = ₹ 120
So, ₹ 120 is paid for his over time at ₹ 8 per h.
∴ Total number of overtime working hours = 120/8 = 15 h
Total working hours = (160 + 15) = 175 h
