21 chaperones are needed for 420 students.
Step-by-step explanation:
No. of juniors = 148
No. of seniors = 272
Total = 148+272 = 420 students
3 chaperones = 60 students
1 chaperone = 
Ratio of chaperon to students = 1:20
Let,
x be the number of chaperons for 420 students.
Ration of chaperones to students = x:420
Using proportion
Ratio of chaperones to students :: Ratio of chaperons to students

Product of mean = Product of extreme

Dividing both sides by 20

21 chaperones are needed for 420 students.
Keywords: ratio, proportion
Learn more about ratios at:
#LearnwithBrainly
Answer:
Area = 67.5 m²
Perimeter = 69 m
Step-by-step explanation:
<h3>Area of triangle:</h3>
b = 27 m & h = 5 m


<h3>Perimeter of triangle:</h3>
Perimeter = sum of all sides
= 27 + 34 + 8
= 69 m
1/2 Because I say because I say so
The answers is the picture I posted. I did in khan academy and it was right.