Answer:
20.5
Explanation:
Doubling Formula:
Doubling Formula:
�
=
�
(
2
)
�
�
y=a(2)
d
t
�
=
5210
�
=
490
�
=
6
y=5210a=490d=6
d is the doubling time
Plug in:
Plug in:
5210
=
5210=
490
(
2
)
�
6
490(2)
6
t
Solve for
�
:
Solve for t:
5210
490
=
490
5210
=
490
(
2
)
�
6
490
490
490(2)
6
t
Divide by 490
10.63265306
=
10.63265306=
2
�
6
2
6
t
log
(
10.63265306
)
=
log(10.63265306)=
log
(
2
�
6
)
log(2
6
t
)
Take the log of both sides
log
(
10.63265306
)
=
log(10.63265306)=
�
6
log
(
2
)
6
t
log(2)
Bring exponent to the front
log
(
10.63265306
)
log
(
2
)
=
log(2)
log(10.63265306)
=
�
6
6
t
Divide by log(2)
3.41042972
=
3.41042972=
�
6
6
t
Divide in calculator
6
(
3.41042972
)
=
6(3.41042972)=
�
t
Multiply by 6
20.462578309
=
20.462578309=
�
t
�
≈
t≈
20.5
20.5