A dental insurance policy covers three procedures; orthodontics, fillings and extractions. During the life of the policy, the probability that the policyholder needs
i) Orthodontics work is
ii) Orthodontics work or filling
iii) Orthodontics work or an extraction is
iv) A filling and an extraction is
The need for orthodontic work is independent of the need for a filling and is independent of the need for an extraction. Calculate the probability that the policyholder will need a filling or an extraction during the life of the policy.
A) 7/24 B) 3/8 C) 2/3 D) 17/24 E) 5/6