The fraction of boys to total students would be 5/8
The fraction of boys to girls would be 5/3
42 is 21% of 200. This is because 200*0.21 = 42.
$23.40
Since we know how much Olivia spent total, and we know how much she spent on the sunglasses, we just subtract 16.35 from 39.74, and the final answer is 23.40