I haven't actually studied radiation, I think last time I guessed, and this question isn't a radiation subject practise question, it is a standalone question in a booklet with various unrelated questions if that makes sense. That booklet is notorious for badly worded questions and in some cases downright incorrect so I want to separate my own factual mistakes from their bad wording-induced errors. So I hope you don't mind if I ask another question.
How would you rephrase this question to make it clearer? I ask because I want to know what part of the wording is confusing me so if they come up with a similar question and I am unfamiliar with the actual topic, which in this case is radiation given to a person (or absorbed by a person, as 'given to' is different to 'absorbed by'), I would know whether I should multiply or divide. (If the question was just said "Gy = J kg−1, J is 0.12, kg is 60, find Gy" I would have divided by 60 and be done.)
To help me answer the question, I tried to replace the word "radiation" in the first sentence to "anaesthetics" and "Joules" to "micrograms" and it makes me want to multiply 0.12 micrograms needed to be "deposited [into the patient] per kilogram of body tissue" by 60kg to get the dose needed (to hypothetically knock out a 60kg person) and that dose is provided by the PET machine. I see deposit as the act of giving the recipient, eg deposit money into a bank, deposit into a person's body etc. I do not see similarity in the words "absorbed" and "deposited" and did not see that the question has given me the total energy absorbed because to me the word dosage per kilo means you need X amount per kilo of body weight, therefore multiply by body weight.
Ahh wait I think I just figured it out, is "Gray" not a unit of dosage and they used the word dosage wrong?