What’s the answer for the question please hurry I have 1 day

Hi i’m not sure how to do question 20 if u could explain how to do it that’d b great

Situation: find the age of the skull to the nearest year, enter the correct answer. a hiker in africa discovers a skull that contains 32% of its original amount of c- 14. done n = noekt 00000 no = inital amount of c-14 (at time t = 0) n = amount of c-14 at time t k = 0.0001 t = time, in years

Find the inverse of the given function. f(x)= -1/2sqr x+3, x greater than or equal to -3