Bubba takes his medicine and soon thereafter 400 mg has been absorbed into his bloodstream. If the half life of this medicine is every 90 minutes, how many hours after taking his medicine will the amount in his bloodstream be reduced to 50 mg?
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after 1*90 minutes there are 200 mg
after 2*90 minutes there are 100 mg
after 3*90 minutes there are 50 mg
3*90=270
90 = 1.5 hrs
3*1.5=4.5 hours
270/60=4.5
after 2*90 minutes there are 100 mg
after 3*90 minutes there are 50 mg
3*90=270
90 = 1.5 hrs
3*1.5=4.5 hours
270/60=4.5
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It will need to go down by 350mg because 400-50=350. Also, in 3 hours(180 minutes) it will change by 1mg. We can therefore set up an equation:
x/3=350 ---> so x=350*3=1050
So it will be 1050 hours before being reduced to 50 mg.
x/3=350 ---> so x=350*3=1050
So it will be 1050 hours before being reduced to 50 mg.
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After 90 minutes = 400 mg becomes 200mg
After 180 minutes = 200 mg becomes 100 mg
After 270 minutes = 100 mg becomes 50 mg
ANSWER 270 minutes OR 4.5 hours later.
After 180 minutes = 200 mg becomes 100 mg
After 270 minutes = 100 mg becomes 50 mg
ANSWER 270 minutes OR 4.5 hours later.
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Richard M is totally right