Patrick purchased some supplies for his guitar students. He bought 25 guitar picks and 25 guitar strings since they only cost $1 more than 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 the cost of one guitar pick is c.
Since Patrick bought 25 guitar picks at c dollars each, he spent a total of 25c dollars on guitar picks.
The cost of the 25 guitar strings is 25c + 1 dollar since they only cost $1 more than the guitar picks.
Patrick spent a total of 25c + 1 dollars on guitar strings and picks which adds up to $40.
So, 25c + 1 = $40.
25c = $40 - $1 = $39.
The cost of one guitar string is 39/25 = $<<39/25=1.56>>1.56. Answer: \boxed{1.56}.