A man is paid ? 5 per h for regular working day and ? 8 per h overtime. A regular working day has 8 h and a regular week has 5 working days. If he earns ? 920 in 4 weeks, then what is the total number of hours that he worked assuming that he was present on all regular working days?

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