Illustration 9 In a factory, payment of wage bonus is made to the workmen based on percentage of time saved of time allowed in the following scale: Time saved (% of standard) Bonus (% of time saved) Upto 20% 10% Above 20% upto 40% Plus 25% of time saved above 20% upto40% Above 40%. Plus 33 1/3% of time saved beyond 40% Calculate the earnings of a worker who completes a job in 57 hours, against a standard time of 100 hours. The normal wage rate is $5 per hour