A DVD that cost 140 soles is sold with a profit of 20% of the selling price. What is the selling price in soles?

1. Problem Description

A DVD that cost 140 soles is sold with a profit of 20% of the selling price. What is the selling price in soles?

2. Solution Steps

Let $C$ be the cost of the DVD, which is 140 soles. Let $S$ be the selling price. The profit is 20% of the selling price, which is $0.20S$.

The selling price is equal to the cost plus the profit. Thus, we can write the equation:

$S = C + 0.20S$

We are given that $C = 140$. Substitute this value into the equation:

$S = 140 + 0.20S$

Subtract $0.20S$ from both sides:

$S - 0.20S = 140$

$0.80S = 140$

Divide both sides by 0.80:

$S = \frac{140}{0.80}$

$S = \frac{1400}{8}$

$S = \frac{700}{4}$

$S = \frac{350}{2}$

$S = 175$

3. Final Answer

The selling price is 175 soles. The answer is D) 175.