How much of each chemical is needed to make 750 kg of the plant food, if a plant food is to be made from three chemicals and the mix must include 60% of the first and second chemicals, the second and third chemicals must be in a ratio of 4 to 3 by weight?
1 Answer
1st chemical 50 kg, 2nd chemical 400 kg, 3rd chemical 300 kg
Explanation:
Let
a+b+c=750 and
a+b=60%of 750=750⋅60100=450
Clearly
Now ratio of
bc=43⇔3b=4c
Since
3b=3(400)=1200
Hence
a+b=450⇒a=450−400=50 kg
Thus chemicals