Patrick purchased some supplies for his guitar students. He bought 25 guitar picks and 25 guitar strings since they only cost 1 more than the guitar picks. He spent a total of 40. If c is the cost of one guitar pick, find the cost of one guitar string
Let's assume that the cost of one guitar pick is c.
The cost of one guitar string is c + 1 since they cost 1 more than the guitar picks.
Patrick bought 25 guitar picks, so he spent 25 * c on guitar picks.
He bought 25 guitar strings, so he spent 25 * (c + 1) on guitar strings.
Since he spent a total of 40, we can write the equation 25c + 25(c + 1) = 40.
Combining like terms, we get 25c + 25c + 25 = 40.
Combining like terms again, we get 50c + 25 = 40.
Subtracting 25 from both sides, we get 50c = 15.
Dividing both sides by 50, we get c = 15 / 50 = <<15/50=0.3>>0.3.
Therefore, the cost of one guitar string is 0.3 + 1 = <<0.3+1=1.3>>1.3. Answer: \boxed{1.3}.