Question

You go to the doctor and he gives you 11 milligrams of radioactive dye. After 12 minutes, 7.75 milligrams of dye remain in your system. To leave the doctor's office, you must pass through a radiation detector without sounding the alarm. If the detector will sound the alarm if more than 2 milligrams of the dye are in your system, how long will your visit to the doctor take, assuming you were given the dye as soon as you arrived

Answer 1

In (16.8+12=) 28.8 minutes the person will be left only with 2mg of dye in the body and be able to leave the doctor's office after being injected with 11 mg

Explanation:

After 12 minutes, 7.75 milligrams of dye remain in your system.

This means that 11- 7.75= 3.25 milligrams of dye are used up in 12 minutes

7.75-2= 5.75 milligrams still needs to be used up

Dye Minutes

3.25 12

5.75 x

x= 12*5.75/3.25

x= 16.8 minutes

5.75 mg will be used up in 16.8 minutes

In (16.8+12=) 28.8 minutes the person will be left only with 2mg of dye in the body and be able to leave the doctor's office.