Bill spent less than $26 on a magazine and five composition books. The magazine cost $4.

Let's say the cost of the five composition books is "x."

Since the total cost is less than $26, the cost of the composition books must be less than $26 - $4 = $<<26-4=22>>22.
Hence, the cost of the five composition books is less than $22.
That means "x" is less than $22.
Therefore, the maximum possible value of "x" is $21.99.
Hence, Bill spent more than $4 + $21.99 = $<<4+21.99=25.99>>25.99 in total. Answer: \boxed{25.99}.

To find out how much Bill spent on five composition books, we can subtract the cost of the magazine from the total amount he spent.

Given that the magazine cost $4 and Bill spent less than $26, we can write an inequality: x < $26, where x represents the total amount Bill spent on the magazine and composition books.

Using this inequality, we can solve for x:

x - $4 < $26

Adding $4 to both sides of the inequality:

x < $30

So, Bill spent less than $30 on the magazine and the composition books.

To find out how much Bill spent on the five composition books, we need to subtract the cost of the magazine from the total amount Bill spent.

Total amount spent = Cost of magazine + Cost of composition books

Total amount spent = $4 + Cost of composition books

Since Bill spent less than $26, we can write the inequality:

Total amount spent < $26

Substituting the expression for the total amount spent:

$4 + Cost of composition books < $26

Now, we can isolate the Cost of composition books:

Cost of composition books < $26 - $4

Cost of composition books < $22

So, Bill spent less than $22 on the composition books.