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

### Instruction:
Alice's white water rafting class is composed of 40 students and 10 instructors, including herself.  She has 20 life vests on hand.  20% of her students are bringing life vests.  How many more life vests will Alice need to get so that entire class has one?

### Response:
 Asilimia 20 ya wanafunzi wake 40 watakuja na vifaa vyao vya kuokoa maisha, hivyo .20*40 = <<.20*40=8>>8 wanafunzi watakuja na vifaa vyao vya kuokoa maisha.
Alice ana vifaa vya kuokoa maisha 20 tayari, hivyo na wale 8 watakaokuja na vifaa vyao, ana jumla ya vifaa vya kuokoa maisha 20+8 = <<20+8=28>>28.
Kuna jumla ya watu 50 katika darasa ikiwa ni pamoja na walimu, hivyo anahitaji 50-28 = <<50-28=22>>22 zaidi vifaa vya kuokoa maisha.