The group attended to the museum. They were 8 girls and 6 adults. So, we should calculate the total paid amount for the 6 adults, then calculate the paid amount for the 8 girls and then add up this two results.
The ticket for an adult costs $50. Since we have 6 adults, the amount paid for the adults' ticket was
So the adults' tickets costed 300. For the girls, one child ticket costs $30. So, the amount paid for the girls' tickets was
So the total amount paid is 300+240 = 540.