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

### Instruction:
Zack has traveled to twice the number of countries Patrick traveled to. Patrick traveled to three times the number of countries Joseph traveled to. Joseph traveled to half the number of countries George traveled to. If George traveled to 6 countries, how many countries did Zack travel to?

### Response:
 Joseph alisafiri nchi 6 / 2 = <<6/2=3>>3.
Patrick alisafiri nchi 3 * 3 = <<3*3=9>>9.
Hivyo, Zack alisafiri nchi 2 * 9 = <<2*9=18>>18.