Answer:
70 people
Explanation:
To find the total number of people at the fair, we need to first find the number of people who are 16 years old or older. We can do this by subtracting the number of people under 16 from the total number of people at the fair:
total number of people = number of people under 16 + number of people 16 or older
Since 70% of the people at the fair are under 16, that means 100% - 70% = 30% of the people at the fair are 16 or older.
We also know that one-third of the people who are 16 or older are teachers, so there are 1/3 * 21 teachers = 7 people in this group.
Now we can substitute these values into the equation above to solve for the total number of people:
total number of people = number of people under 16 + number of people 16 or older
= number of people under 16 + 7
We can find the number of people under 16 by dividing the number of teachers (21) by the fraction of people who are 16 or older:
number of people under 16 = 21 teachers / (1/3)
= 21 teachers * 3
= 63 people
Substituting this value into the equation above, we get:
total number of people = 63 people + 7 people
= 70 people
So there are a total of 70 people at the school fair.