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

### Instruction:
A pharmacy is buying enough tubs for them to make their prescriptions this week. They already have 20 tubs left in storage but they need a total of 100 tubs for the week. Of the tubs they still need to buy, they buy a quarter from a new vendor then decide to go to their usual vendor for the rest. How many tubs is the pharmacy going to buy from the usual vendor?

### Response:
 Tayari wana vikombe 20 kwenye ghala, hivyo wanahitaji kununua vikombe 100 vinavyohitajika - vikombe 20 vilivyobaki kwenye ghala = <<100-20=80>>80 vikombe.
Kutoka kwa muuzaji mpya, wanunua vikombe 80 / 4 = <<80/4=20>>20 vikombe.
Baada ya kununua vikombe 20 kutoka kwa muuzaji mpya, sasa wana jumla ya vikombe 20 + 20 kwenye ghala = <<20+20=40>>40 vikombe.
Hivyo, duka la dawa linatarajia kununua vikombe 100 vinavyohitajika - vikombe 40 vilivyopo kwenye ghala = <<100-40=60>>60 vikombe kutoka kwa muuzaji wao wa kawaida.