There are 300 students in the 6th grade. The ratio of students who play an instrument to all students is 2:5. Hou
many people in 6th grade play an instrument?
By setting up the equation 2/5=x/300, we can cross cancel, changing the equation into 5x=600, and by dividing both sides by 5, the 5 in 5x cancels out and 600 divided by 5 is 120.
