The answer is:
Benji requires 90mL per injection.
Why?From the statement we know that dog's weight is 12 kg, and daily injections are required for 3 days, the dose rate is 7.5 mg/kg, so we need to calculate how many mL per injection does Benji require.
We have that:
If the dose rate is 7.5 mL per each Kg, how many mL are required for 12 Kg? We can set it up using the following relation:
Hence, we have that there are needed 90 mL per injection.
Have a nice day!