An employment agency pays heavy equipment operators $129 per day and general laborers $96 per day. If 35 people were hired and the payroll was $4185, how many heavy equipment operators were employed? How many laborers?

If 35 people were hired at $96 per day, the daily payroll would be

35*96=3500-140=$3360

Actual payroll is 4185, or (4185-3360) = $825 more.

At (129-96) = $33 more per operator, there are 825/33=25 operators, hence 35-25=10 general laborers.

Alternative:

L=number of labourers

(35-L) = number of operators

Total daily payroll

=96L+129 (35-L) = 4185

simplify

33L=129*35-4185=330

L=330/33=10

THere are 10 labourers and (35-10) = 25 operators.