Dried fruit

The manufacturer produces a mixture of dried fruit. He purchased:

10 kg pineapple for 200 Kc/kg
2 kg papaya for 180 kc/kg
1 kg of banana for 400 Kc/kg

How many kgs of raisin for 80 Kc/kg must be put into the mix by the manufacturer so that the production price of the mixture is 120 Kc/kg?

Final Answer:

m =  30 kg

Step-by-step explanation:

$$\begin{gathered} 120=\frac{10\cdot 200+2\cdot 180+1\cdot 400+m\cdot 80}{10+2+1+m} \\ 120\cdot (10+2+1+m)=10\cdot 200+2\cdot 180+1\cdot 400+m\cdot 80 \\ 40m=1200 \\ m=\frac{1200}{40}=30 \\ m=30=30\text{kg} \end{gathered}$$

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