The Ratio of the cost price of a pencil and a pen is 3 : 7. The ratio of the selling price is 1 : 4. If the loss incurred is equal after selling both products, then what is the ratio of the cost price and selling price of a pen?

Question: The Ratio of the cost price of a pencil and a pen is 3:7. The ratio of the selling price is 1:4. If the loss incurred is equal after selling both products, then what is the ratio of the cost price and selling price of a pen?

Answer:
Let, cost price of a pencil = 3x
pen = 7x
Selling price of a pencil = y
pen = 4y
According to the question,
3x- y = 7x- 4y
→ 4y-y =7x -3x
→ 3 y = 4x
∴ y = 4/3 x

The ratio of the cost price of a pen: the selling price of a pen = 7x : 4 (4/3 x)
= 21 : 16