A building contractor employs 80 men. Some of the men are paid $12 a day, some $16 a day, and the rest at$18 a day. Altogether they are paid $1180 per day. The number of men being paid $16 is four times the number of men being paid $18. How many men are being paid each of the values

Solution:

     no. of men paid $ 18 = x

     no. of men paid $ 16 = 4x

     no. of men paid $ 12 = 80 - 5x

     12(80 - 5x) + 16(4x) + 18x = 1180

     960 - 60x + 64x + 18x = 1180

     22x = 1180 - 960 = 220

         x = no. of men paid $ 18 = 220/22 = 10

       4x = no. of men paid $ 16 = 40

   80 - 5x = no. of men paid $ 12 = 30