A man’s basic pay for a 40 hour week is Rs. 20 overtime is paid for at 25 % above the basic rate, in a certain week he worked overtime and his total wage was Rs. 25. He therefore worked for a total of:________?

A. 45 hours
B. 47 hours
C. 48 hours
D. 50 hours
Explanation:
Basic rate per hour = Re. (20/40) = Re. 1/2.
Overtime per hour = 125 % of Re. 1/2 = Re.5/8.
He worked x hours overtime.
Then 20 + 5/8 x = 25 (or) = 5/8 x = 5
X = 40/5 = 8 hours
=> he worked in all for (40 + 8) = 48 hours.