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

### Instruction:
Edward the plumber is replacing a pipe in a bathroom wall.  He needs to use 40 feet of copper pipe to complete the job.  For every 5 feet of pipe, Edward must use one tightening bolt, and for every bolt, he uses two washers.  He buys a bag of 20 washers for the job.  After he completes the bathroom job, how many washers will be remaining in the bag?

### Response:
 Ikiwa Edward anahitaji kutumia miguu 40 ya bomba, na kwa kila miguu mitano ya bomba anatumia bolt moja, basi atatumia 40/5 = <<40/5=8>>8 bolts za kufunga.
Ikiwa kwa kila bolt anatumia washers mbili, basi atatumia bolts 8 x 2 = <<8*2=16>>16 washers.
Washers ziada zitahitajika kukamilisha kazi. Edward ananunua mfuko wenye washers 20 ili kuhakikisha ana washers za kutosha kukamilisha kazi.
Baada ya kazi kukamilika, Edward atakuwa ametumia washers 16.
Hivyo, atabakiwa na washers 20 - 16 = <<20-16=4>>4 kwenye mfuko.