Answer:
166,833
Step-by-step explanation:
t
n
=
a
+
(
n
−
1
)
d
999
=
3
+
(
n
−
1
)
3
999
=
3
+
3
n
−
3
999
=
3
n
n
=
333
We can now use the formula
s
n
=
n
2
(
2
a
+
(
n
−
1
)
d
)
)
to determine the sum.
s
333
=
333
2
(
2
(
3
)
+
(
333
−
1
)
3
)
s
333
=
333
2
(
1002
)
s
333
=
166
,
833
Hopefully this helps!
