Answer:
100 students who attended the tournament.
Explanation:
Let's use algebra to solve the problem. Let's call the number of students who attended the tournament "s" and the number of adults who attended the tournament "a". Then we can write two equations based on the information given:
s + a = 450 (equation 1)
7s + 10a = 4200 (equation 2)
Equation 1 represents the total number of people who attended the tournament, which is 450. Equation 2 represents the total amount of money collected in ticket fees, which is $4,200.
To solve for "s", we can use elimination or substitution. Let's use elimination. We can multiply equation 1 by -7 to get:
-7s - 7a = -3150 (equation 3)
Now we can add equation 3 to equation 2:
-7s - 7a + 7s + 10a = -3150 + 4200
Simplifying the left side and solving for "a", we get:
3a = 1050
a = 350
So there were 350 adults who attended the tournament. We can substitute this value back into equation 1 to solve for "s":
s + 350 = 450
s = 100
Therefore, there were 100 students who attended the tournament.