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

### Instruction:
Sue and her sister buy a $2,100 car.  They agree to split the cost based on the percentage of days use.  Sue's sister will drive the car 4 days a week and Sue will get the rest of the days.  How much does Sue have to pay?

### Response:
 Sue atatumia gari siku 7-4=3 kwa wiki.
Hivyo, anapaswa kulipa 2100*3/7=$<<2100*3/7=900>>900.