Josh ingests 800mg of ibuprofen. His body metabolizes (uses up) 20% of the medicine
per hour. How much medicine is remaining in his system after four hours? Round your
answer to the nearest gram.

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 :

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Amount of medicine left after 2 hour :

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Amount of medicine left after 3 hour :

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Amount of medicine left after 4 hour :

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Therefore , 328 mg medicine is remaining in his system after four hours .