#### Answer

$D(3)\approx 27.4$ milligrams.

#### Work Step by Step

We are given:
$D(t)=50e^{-0.2t}$
To find the amount of the drug left, we plug in $t=3$ hours:
$D(3)=50e^{-0.2*3}\approx 27.4$ milligrams.

Published by
Brooks Cole

ISBN 10:
1305115546

ISBN 13:
978-1-30511-554-5

$D(3)\approx 27.4$ milligrams.

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