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Mathematics
Mathematics
Problem
A culture of bacteria grows according to
N
(
t
)
=
e
0.8
t
N(t)=e^{0.8t}
N
(
t
)
=
e
0.8
t
, where
N
N
N
is the number of bacteria and
t
t
t
is time in hours. Which logarithmic equation must be solved to find the time
t
t
t
when
N
=
20
N=20
N
=
20
? a)
ln
0.8
=
20
t
\ln 0.8 = 20 t
ln
0.8
=
20
t
b)
ln
20
=
0.8
t
\ln 20 = 0.8 t
ln
20
=
0.8
t
c)
ln
(
20
t
)
=
0.8
\ln\left(20^{\,t}\right)=0.8
ln
(
2
0
t
)
=
0.8
d)
log
20
e
=
0.8
t
\log_{20} e = 0.8 t
lo
g
20
e
=
0.8
t
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