328 mg medicine is remaining in his system after four hours .
Step-by-step explanation:
Here we have , Josh ingests 800 mg of ibuprofen. His body metabolizes (uses up) 20% of the medicine per hour.We need to find How much medicine is remaining in his system after four hours .Let's find out:
According to question , Josh ingests 800 mg of ibuprofen and His body metabolizes (uses up) 20% of the medicine per hour . let amount of medicine left after 4 hours is x , So Amount of medicine left after 1 hour :
⇒ [tex]800-\frac{800(20)}{100} = 800-160 = 640 mg[/tex]
Amount of medicine left after 2 hour :
⇒ [tex]640-\frac{640(20)}{100} =512 mg[/tex]
Amount of medicine left after 3 hour :
⇒ [tex]512-\frac{512(20)}{100} =409.6 mg[/tex]
Amount of medicine left after 4 hour :
⇒ [tex]409.6-\frac{409.6(20)}{100} =328 mg[/tex]
Therefore , 328 mg medicine is remaining in his system after four hours .
