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

### Instruction:
Stephen ordered 2 large pizzas, both cut into 12 slices.  He ate 25% of the pizza.  His friend Pete ate 50% of the remaining pizza.  How many slices are left over?

### Response:
 Stephen alinunua pizza 2, kila moja imekatwa vipande 12 hivyo jumla ni vipande 2*12 = <<2*12=24>>24.
Alikula 25% ya pizza hivyo inabaki 24*.25 = 6 vipande.
Hivyo inabaki 24-6 = <<24-6=18>>18 vipande.
Vipande 18 vimebaki na Pete anakula 50% ya vipande 18 hivyo ni vipande 18*.50 = <<18*.50=9>>9.
Kama kulikuwa na vipande 18 na Pete alikula vipande 9 basi inabaki vipande 18-9 = <<18-9=9>>9.