The charge of admission fee for each person is $ 30.
The Cost of P people is C.
The equation relating C to P can be determined by using unitary method.
The cost of 1 person is 30
The cost of P person will be,
Thus, C=30P is the required equation.
The cost of admission for 19 people can be determined by substituting the value of P=19 in the above equation,
Thus, the required cost of admission is $ 570.