Answer:
To find out for how much the shopkeeper should sell the article to gain 20%, we can use the following steps:
1. First, let's determine the cost price (CP) of the article.
2. Then, we'll calculate the selling price (SP) needed to gain a 20% profit.
Given that the shopkeeper initially sells the article for $1600 and incurs a 20% loss, we can find the cost price (CP) using the formula:
CP = SP / (1 - Loss Percentage)
CP = $1600 / (1 - 20%) = $1600 / 0.8 = $2000
So, the cost price (CP) of the article is $2000.
Now, to find the selling price (SP) needed to gain a 20% profit, we can use the formula:
SP = CP + Profit Percentage * CP
SP = $2000 + 20% * $2000 = $2000 + $400 = $2400
The shopkeeper should sell the article for $2400 to gain a 20% profit.