9. An article was sold at a profit of 12%. Had it been sold for Nu 80 more, there would be a profit of
20%. Find
1) the cost price of the article
2)the selling price of the article​

Respuesta :

Answer:

The cost price of the article was Nu 1,000

The original selling price was Nu 1,120

The second selling price was Nu 1,200

Step-by-step explanation:

System of Equations

Let's call:

x = Original selling price of the article

y = Cost of the article

The first condition implies that the difference between the selling price and the cost price (the profit) is 12%. Recall the profit % is always calculated with respect to the cost, that is, the profit at the first condition is:

0.12y = Original profit

Setting up the equation, we have:

[tex]x-y=0.12y[/tex]

The second condition states the selling price is 80 Nu more than before, that is:

x+80= Second selling price of the article

y = Cost of the article (it doesn't change)

The profit of this condition is 20%, thus:

0.2y = Second profit

This produces a second equation:

[tex]x+80-y=0.2y[/tex]

Let's put both equations together to form a system of equations:

[tex]x-y=0.12y[/tex]

[tex]x+80-y=0.2y[/tex]

Operating on both equations:

[tex]x=1.12y[/tex]

[tex]x=1.2y-80[/tex]

Equating both equations, we have an equation with only y's:

[tex]1.12y=1.2y-80[/tex]

Subtracting 1.2y on each side:

[tex]1.12y-1.2y=-80[/tex]

Operating:

[tex]-0.08y=-80[/tex]

Solving:

[tex]\displaystyle y=\frac{-80}{-0.08}=1,000[/tex]

a)

The cost price of the article was Nu 1,000

b) The selling price of the article will be calculated in both cases:

Original selling price: x=1.12y= 1.12*1000=1,120

The original selling price was Nu 1,120

The second selling price was x+80=1,200

The second selling price was Nu 1,200