The cost of variety A wheat flour is Tk. 42 per kg and variety B wheat flour is Tk. 35 per kg. If both variety A and variety B are mixed in the ratio of 3 : 2, then the price per kg of the mixed variety of wheat flour is:

Question: The cost of variety A wheat flour is Tk. 42 per kg and variety B wheat flour is Tk. 35 per kg. If both variety A and variety B are mixed in the ratio of 3 : 2, then the price per kg of the mixed variety of wheat flour is:

Solution:
Let,
Quantity of variety A flour is 3x kg.
Quantity of variety B flour is 2x kg.
The price per kg of the mixed variety of flour is y taka
∴ Total price of variety A flour is 42 × 3x = 126x Taka
∴ Total price of variety B flour is 35 × 2x = 70x Taka

ATQ,
126x + 70x = y(3x + 2x)
⇒ 196x = y × 5x
⇒ y = (196x)/(5x)
∴ y = 39.2
Therefore, the price per kg of the mixed variety of wheat flour is Tk. 39.20