412 + 162 + 347 = 921. Because it is closer to 900 than 1,000, the answer is 900.
Answer:
32.
1st get the total age of the students
x/20 = 11
x=11x20
x =220 (total age of students)
add y ( teachers age) to the equation
(220 + y)/21=12
y= 32
Since it is the perimeter you add all the sides, so it is 5 1/2 + 5 1/2 * 6= 15, so the perimeter is 15:)
