Zombo's class is 33:22 or 3:2
Stolarski's class is 55:33 or 5:3
15 students in Zombos
9 boys 6 girls
32 students in Stolarski
20 boys 12 girls
Together is 29 boys and 18 girls
29:18 boys to girls
we know that
In an Arithmetic Sequence the difference between one term and the next is a constant
This problem is an Arithmetic Sequence
where
the first term is 
and
the common difference is 
In general we can write an Arithmetic Sequence as a rule

where
a1 is the first term
d is the common difference
so

<u>Find the term a7</u>
![an=a1+d*(n-1)\\ \\ a7=23+(-2)*[7-1]\\ \\\\ a7=23-12\\ \\\\ a7=11](https://tex.z-dn.net/?f=%20an%3Da1%2Bd%2A%28n-1%29%5C%5C%20%5C%5C%20%20a7%3D23%2B%28-2%29%2A%5B7-1%5D%5C%5C%20%5C%5C%5C%5C%20a7%3D23-12%5C%5C%20%5C%5C%5C%5C%20%20%20%20a7%3D11%20%20%20%20%20)
therefore
<u>the answer is</u>

Perimeter = sum of all the sides
let x = one side
longer side = x + 10
Perimeter = x + x + x + x + 10
62 = 4x + 10
4x = 52
x = 13
Longer side = 23
Area = (10+23)x2/10
= 6.6
The answer to your question is x = 8