To determine how much US dollars are needed to buy a bilum that costs K400, we can use the exchange rate provided:
- The exchange rate is K1.00 = US$0.30.
- To find the cost in US dollars, we can multiply the cost in PNG Kina by the exchange rate.
First, we can calculate the amount in US dollars:
\[ \text{Cost in US dollars} = \text{Cost in Kina} \times \text{Exchange rate} \] \[ \text{Cost in US dollars} = 400 , \text{Kina} \times 0.30 , \text{US dollars/Kina} \] \[ \text{Cost in US dollars} = 400 \times 0.30 = 120 , \text{US dollars} \]
So, Donald would need $120 US dollars to purchase the bilum.