# find cost price

• May 23rd 2008, 08:42 PM
neha1
find cost price
a man sells an article at a profit of 25%.if he had bought it at 20% less and sold it for the amount 10.50 less,he would have gained 30%.find the cost price of article?
• May 23rd 2008, 10:59 PM
Moo
Hello,

Quote:

Originally Posted by hena
a man sells an article at a profit of 25%.if he had bought it at 20% less and sold it for the amount 10.50 less,he would have gained 30%.find the cost price of article?

Let X be the cost price of the article, and let Y be the price he sells the article the first time.

1st sentence
Making a profit of 25% is like selling it to 1.25 times the cost price.

So $\displaystyle \boxed{Y=1.25 ~X}$

2nd sentence
If he had bought it 20% less, it means that the cost price becomes $\displaystyle 0.80 ~X$
If he sells it for the amount 10.50 less, this means that he sells it at the price $\displaystyle Y-10.50$

While doing this, he makes a profit of 30%. So reasoning just as before, we get :

$\displaystyle \boxed{(0.80 ~\cdot X) ~\cdot 1.30=Y-10.50}$

Now, solve for X :)
• May 25th 2008, 08:19 AM
neha1
plz help
am not getting aproper value of x...
plz help me out..
the option they gave me is
55,45,50,60
• May 25th 2008, 08:23 AM
Moo
Quote:

Originally Posted by hena
am not getting aproper value of x...
plz help me out..
the option they gave me is
55,45,50,60

Well, I get 50...

$\displaystyle Y=1.25 X$

Substituting in $\displaystyle (0.80 ~\cdot X) ~\cdot 1.30=Y-10.50$ :

$\displaystyle (0.80 ~\cdot X) ~\cdot 1.30=1.25 X-10.50$

0.8*1.3=1.04

$\displaystyle 1.04 X=1.25 X-10.50$

$\displaystyle 0.21 X=10.50$