A group of 10 people is charged $12 + $6 = $18 each.
So, 10 people pay $18 x 10 = $<<18*10=180>>180.
A group of 5 people pays $12 x 5 = $<<12*5=60>>60 for the admission.
Thus, the aqua park earns a total of $180 + $60 = $<<180+60=240>>240.
#### 240