# Percent word problem - calculate store cost

Here's a word problem having to do with percentages, and the answer doesn't make sense. A furniture store is selling a desk for $300. If the store makes a 25% profit on the sale, what is the store's cost for the desk? The answer is $240 but how?

Thanks.

Let us say that $x$ is the cost for the store. The store makes a profit of $25$% which means that the selling price is $1.25 x$; so $1.25 x=300$ then $x=300/1.25=240$.

Let's say the cost of the desk for the store is 100%. We know 25% more than that is \$300. Hence, 125% of the cost price of the desk is \$300, and the original price is therefore $100\times \frac{\$300}{125}$. Since$\$300/125$ = 1% of cost price, and then we just multiply by 100 to find the original 100%.

Use the formula:

$$\frac{\text{percent of change}}{100} = \frac{\text{change in price}}{\text{original price}}$$

Let $x$ = the original price.

Then

$$\frac{1}{4} = \frac{300-x}{x}$$

$x =$ $240. • Thanks, skullpatrol. BTW, how do you enter the equations on this site? – Alex Mar 31 '14 at 4:20 • This may help :-) – skullpatrol Mar 31 '14 at 12:28 If the store makes a$25$% on$300.

So, $300 is 125% of store's cost. Let the store's cost is x dollars. Now, make the proportion, $$\dfrac{300}{x}=\dfrac{125}{100}$$ $$125x=30000$$ $$x=\dfrac{30000}{125}$$ $$x=240$$ So, the store's cost is$240.