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

### Instruction:
Trey is hanging wall decorations around his house. He uses a nail for each of two-thirds of them, a thumbtack for each of two-fifths of the rest, and a sticky strip for each of the other decorations. He used 15 sticky strips. How many nails did Trey use?

### Response:
 Trey ametumia vibandiko vya kunata 15 kwa 3/5 ya mapambo yaliyosalia baada ya kutumia kucha, hivyo ametumia vibandiko vya kunata na pini 15 * 3/5 = 25.
Mapambo 75 yalikuwa 2/3 ya mapambo yote, hivyo ametumia mapambo 75 / 2/3 = 150 kwa jumla.
Kucha zilikuwa 1/3 ya mapambo, hivyo Trey ametumia mapambo 150 * 1/3 = 50 kucha.