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 480 zombies in the shopping mall. If the number of zombies doubled every day, how many days ago were there less than 50 zombies in the mall?

### Response:
 Kwanza tafuta idadi ya wazombie iliyokuwepo siku moja iliyopita: 480 wazombie / 2 = <<480/2=240>>240 wazombie
Kisha tafuta idadi ya wazombie iliyokuwepo siku mbili zilizopita: 240 wazombie / 2 = <<240/2=120>>120 wazombie
Kisha tafuta idadi ya wazombie iliyokuwepo siku tatu zilizopita: 120 wazombie / 2 = <<120/2=60>>60 wazombie
Kisha tafuta idadi ya wazombie iliyokuwepo siku nne zilizopita: 60 wazombie / 2 = <<60/2=30>>30 wazombie, ambayo ni chini ya 50, hivyo kulikuwa na chini ya wazombie 50 siku nne zilizopita.