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

### Instruction:
Musa is the class teacher of a class of 45 students. He wants to split them into three groups by age. If a third of the class is under 11 years, and two-fifths are above 11 but under 13, how many students will be in the third group (13 years and above)?

### Response:
 Kundi la kwanza ni theluthi moja ya darasa ambayo ni (1/3)*45 = <<(1/3)*45=15>>15 wanafunzi.
Kuna wanafunzi 15 katika kundi la kwanza, hivyo kuna wanafunzi 45-15 = <<45-15=30>>30.
Kundi la pili ni wawili kati ya tano wa darasa ambayo ni (2/5)*45 = <<2/5*45=18>>18 wanafunzi.
Kuna wanafunzi 18 katika kundi la pili, hivyo kuna wanafunzi 30-18 = <<30-18=12>>12.
Kundi la tatu ni wanafunzi waliosalia ambao ni 13 na zaidi, ambayo ni wanafunzi 12.