54% of what is 216...
0.54x = 216
x = 216 / 0.54
x = 400....so there were a total of 400 people surveyed
The product of the sum of the their rates and the time it took them to finish the job should be equal to one whole job. This may be expressed by the equation,
(1/9 + r) x 6 = 1
Solving for the value of r gives an answer of r = 1/18. Thus, Hector does 1/18 of the job in 1 hour.
Replacing y by x in the first line we'll get x+8x-12=6, so 9x=18, x=2, y=1 being the only solution
