Can you guys please help me with this question

Some boys and girls were asked if they had a pet. one third of the group were boys. there were 20 boys. 20% of the girls had a pet. boys with a pet : girls with a pet = 1 : 5 i need to know how many girls there are.

What is the effect on the graph of the function f(x)=x when f(x) is replaced with -f(x)+4

The function models the number of accidents per 50 million miles driven as a function