Five and one half less than 3 times a number

The jurassic zoo charges $14 for each adult admission and $5 for each child. the total bill for 77 people from a school trip was $565. how many adults and how many children went to the zoo? i

Determine the number of girls in a math class with 87 boys if there are 25 girls for every 75 boys

How do you find the distance of each number from the mean