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

### Instruction:
Three-quarters of the oil from a 4000-liter tank (that was initially full) was poured into a 20000-liter capacity tanker that already had 3000 liters of oil. How many more liters of oil would be needed to make the large tanker half-full?

### Response:
 Mafuta matatu ya robo kutoka tangi lenye ujazo wa lita 4000 yatakuwa 4000*(3/4) = <<4000*(3/4)=3000>>3000 lita
Pamoja na lita 3000 zilizokuwepo tayari katika tangi kubwa, kuna jumla ya lita 3000+3000 = <<3000+3000=6000>>6000 za mafuta.
Tangi lingejaa nusu-jaa kwa (1/2)*20000 = <<(1/2)*20000=10000>>10000 lita za mafuta.
Kwa sasa, kuna lita 6000 katika tangi, hivyo inahitaji lita 10000-6000 = <<10000-6000=4000>>4000 za mafuta ili liwe nusu-jaa.