To find the number of musicians in the marching band, we need to subtract the number of musicians who play only in the jazz band from the total number of jazz band players.
First, let's find the number of musicians who play only in the jazz band. We know that 130 musicians play in both the jazz band and the marching band. Therefore, the number of musicians who play only in the jazz band can be calculated by subtracting the number of musicians who play in both from the total number of jazz band players:
Number of musicians who play only in the jazz band = Total number of jazz band players - Number of musicians who play in both
= 250 - 130
= 120
Now that we know there are 120 musicians who play only in the jazz band, we can calculate the number of musicians in the marching band by subtracting this number from the total number of musicians:
Number of musicians in the marching band = Total number of musicians - Number of musicians who play only in the jazz band
= 375 - 120
= 255
Therefore, there are 255 musicians in the marching band.