Use proportional relationship to solve this mixture problem. The incoming 6th-grade class has a choice between band or choir as an elective.
There are four times as many seats in choir as there are in band. How many students can choose band if there is a total of 250 students?
Let the number of seats in band be x.
According to the problem, the number of seats in choir is four times the number of seats in band, so the number of seats in choir is 4x.
The total number of students is 250, so we have the equation x + 4x = 250.
Combining like terms, we get 5x = 250.
Dividing both sides of the equation by 5, we get x = 250/5 = 50.
Therefore, there are 50 seats in band, so 50 students can choose band.