Answer:
b is not a function
Step-by-step explanation:
To be a function there must be a one to one correspondence.
Each x must only go to one y
b has an x that goes to two different y's
1 goes to 5 and 13. That makes it a relation not a function
Use the geometric mean for right triangles here. Like this

. Cross multiply to get

, and

. That simplifies down to

. Pull out the 9 as a perfect square of 3 and you're left with

, first choice above.
95 is 20% of 475
to check answer do 475 times .2