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 60 ridges on a vinyl record. Jerry has 4 cases, each with 3 shelves that can hold 20 records each. If his shelves are 60% full, how many ridges are there on all his records?

### Response:
 Kwanza, tunahitaji kujua idadi ya rekodi zinazoweza kuingia kwenye rafu zote. Hii inafanywa kwa kufanya 4 * 3 = <<4*3=12>>12 rafu.
Kisha, tunapata idadi ya rekodi zinazoweza kuingia kwenye kila rafu kwa kuzidisha nafasi ya rafu na 60%. 20 * .6 = <<20*.6=12>>12 rekodi zinazoweza kuingia kwenye kila rafu.
Kisha tunazidisha idadi ya rekodi zinazoweza kuingia kwenye kila rafu na idadi jumla ya rafu, tukipata 12 * 12 = <<12*12=144>>144 rekodi zinazoweza kuingia kwenye rafu zote.
Kwa kuwa kila rekodi ina vijito 60, tunazidisha idadi jumla ya rekodi na 60 ili kupata idadi ya vijito, tukipata 60 * 144 = <<60*144=8640>>8640 vijito kama jibu.