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

### Instruction:
The price of a math textbook in the school bookshop is $45. If those sold in bookshops outside the school cost 20% less, how much can Peter save by buying from other bookshops rather than the school's if he wants to buy 3 math textbooks?

### Response:
 20% chini inamaanisha 20/100*45=$9 chini
Bei ya kitabu katika maduka mengine ni $9 chini ya $45 ambayo ni $45-$9 = $36
Vitabu 3 kutoka duka la shule vitagharimu $45*3=$135
Vitabu 3 kutoka duka lingine vitagharimu $36*3=$108
Kwa kununua kutoka duka lingine badala ya la shule, Peter anaweza kuokoa $135-$108 = $27