Below is an instruction that describes a task. Write a response that appropriately completes the request in Swahili. Please answer in Swahili.

### Instruction:
There are 13 3-year-olds, 20 4-year-olds, 15 5-year-olds, and 22 six-year-olds at a particular Sunday school. If the 3 and 4-year-olds are in one class and the 5 and 6-year-olds are in another class, what is the average class size?

### Response:
 Kwanza tafuta idadi jumla ya watoto wenye umri wa miaka 3 na 4: watoto 13 + watoto 20 = <<13+20=33>>33 watoto
Kisha tafuta idadi jumla ya watoto wenye umri wa miaka 5 na 6: watoto 15 + watoto 22 = <<15+22=37>>37 watoto
Kisha ongeza idadi mbili za watoto ili kupata idadi jumla ya watoto: watoto 33 + watoto 37 = <<33+37=70>>70 watoto
Kisha ugawanye idadi ya watoto kwa idadi ya madarasa ili kupata ukubwa wa darasa wastani: watoto 70 / madarasa 2 = <<70/2=35>>35 watoto/darasa