Answer :
Given : The employees in a firm earn Rs. 8.50 an hour for the first 40 hours per week .
And
1.5 times the hourly rate for any hour worked over 40 hours .
So , Per hour rate for first 40 hours = Rs. 8.50
And
According to given information
Per hour rate for over 40 hours = 8.50 1.5 = Rs. 12.75
SO, employee earn if he work 52 hours in one week = Total earning in first 40 hours + Total earning over 40 hours
For first 40 hours he earns = 40 8.50 = 340
And
Over 40 hours he works = 52 - 40 = 12 hour ,
He earns over 40 hours = 12 12.75 = 153
SO, employee earn if he work 52 hours in one week = 340 + 153 = Rs . 493 ( Ans )