Hi swerve,

We're told that a factory that employs 1000 assembly line workers pays each of these workers $5 per hour for the first 40 hours worked during a week and 1½ times that rate for hours worked in excess of 40. We're asked for the total payroll for the assembly-line workers for a week in which 30 percent of them worked 20 hours, 50 percent worked 40 hours, and the rest worked 50 hours? This question is essentially just about some basic Arithmetic and organized note-taking, but there is a potential 'shortcut' if you recognize that since we're dealing with a multiple of 10 workers, we can calculate the pay for 10 workers under these circumstances - and then multiply that total by 100. There's another minor 'shortcut' if we convert all of the hours into 'standard' hours.

IF.... there were 10 employees, then based on the given percentages...
3 employees would work 20 hours
5 employees would work 40 hours
2 employees would work 50 hours

The first group worked a total of 3(20) = 60 hours
The second group worked a total of 5(40) = 200 hours
The third group worked the equivalent of a total of 2(40) + 2(15) = 110 hours (since each overtime hour is the equivalent of 1.5 standard hours).
Total hours worked = 60 + 200 + 110 = 370 hours
(370 hours)($5/hour) = $1850
Multiplying that total by 100, we would have $185,000

Final Answer: B

GMAT assassins aren't born, they're made,
Rich