Find the probability that a randomly selected point within the circle falls in the red shaded area

Question 5 spring semester final exam math evaluate

Hillel is juggling flaming torches to raise money for charity. his initial appearance raises $500\$500 $500 , and he raises $15\$15 $15 for each minute of juggling performance. the amount rr r of money hillel raises is a function of tt t , the length of his performance in minutes. write the function's formula.

Write a story that matches with the expression 42x-5 pls hurry