ShmoopTube

00:02

Here's an unshmoopy question you'll find on an exam somewhere in life...

00:06

These are the first three terms in a sequence.

00:09

How many dots would be in the 5th term of this sequence?

00:12

Here are the potential answers...

00:17

To solve this problem, we can either draw a ton of dots... or go the number route.

00:23

First term: a column of 1, which means 1 dot total.

00:27

Second term: columns of 1, 3, 1, or 5 dots total.

00:32

Third term: columns of 1, 3, 5, 3, 1, or 13 dots total.

00:37

See the pattern yet?

00:40

Fourth term: columns of 1, 3, 5, 7, 5, 3, 1, or 25 dots total.

00:46

Fifth term: columns of 1, 3, 5, 7, 9, 7, 5, 3, 1...

00:51

When we add all the numbers, we get 41.

00:54

So the correct answer is (D).

00:55

As in, "Dot overload."

Full Transcript