11. Malcolm purchased some supplied for his music class. He bought 30 guitar picks and 30 guitar strings since they only cost $1 more than the guitar picks. He spent a total of $75. If c is the cost of one guitar pick, find the cost of one guitar string.
Let's say the cost of one guitar string is s.
The cost of 30 guitar picks is 30*c = 30c
Since they only cost $1 more than the guitar picks, the cost of the 30 guitar strings is 30c + 30*1 = 30c + 30
The total cost of the 30 guitar picks and 30 guitar strings is 75, so 30c + 30 + 30c = 75
This simplifies to 60c + 30 = 75
Subtracting 30 from both sides gives 60c = 45
Dividing both sides by 60 gives c = 45/60 = 0.75
The cost of one guitar string is s = c + 1 = 0.75 + 1 = 1.75. Answer: \boxed{1.75}.