Aptitude - Profit and Loss - Discussion

If c.p of an article is 4 and s.p of an article is 5.

c.p of articles is equal to s.p of 16 article;
So,20*4=16*5=80.

s.p of 20 article is 20*5 = 100.
c.p of 20 article is 20*4 = 80.
Profit is 20.
20/80 *100=25%.

CP of 20= SP of x
sp/cp = 20/x.
sp-cp/cp = 20-x/x.
profit percentage = 25%.
Therefore,25/100 = 20-x/x.
Solving we get x = 16.

CP = 100/article.
SP = 125/article, as we know the profit% is 25%.

Therefore,
CP of 20 articles = SP of x articles.
=> 20 * 100 = x * 125.
=> x = 4 * 4.
=> x = 16 (Ans).

Selling Price of X article is 20 and, we have to find C.P. of this X article.
It can be calculated by using the formula of C.P. which is given below;
C.P. = 100/(100+Gain%) * S.P.

So, let C.P. be X.. And by given data Gain % = 25, and S.P. of X article = 20 putting this values we get,

X(c.p) = 100/(100+25) * 20(s.p).
X= (100/125) * 20,
= 0.8 * 20,
= 16.

@Shahil Shaji.

Nice explanation keep rocking. Thanks.

Thanks for your answer @Surbhi Garg.

Why do we have to assume that CP is Rs. 1?

Cant we solve using equations?

Can you please make me understand by giving more examples?

Hi every one
here this problem is a bit difficult to understand. let me give u an another example then we will come to this.

let c.p. of 1 article is Rs. 4 and
let s.p. of 1 article is Rs. 5

now c.p. of 20 article is 20*4=80
and s.p.of 16 article is 16*5=80
the first line of the question said these r equal that is Rs. 80

now come to our problem above.
let c.p of 1 article is Rs.1
here given that c.p. of 20 article is equal to s.p. of x article

so let us calculate c.p. of 20 article=Rs 20
hence s.p. of x article is Rs. 20
so s.p. of 1 article =20/x

profit on one article= (20/x)-1
% profit=((20/x)-1)*100)/1=25

hence x=16

Let C.P. of 1 article =1.
C.P. of x articles = x.
S.P. of x articles = 1.25x.

Given S.P. of x articales = C.P. of 20 articles.
1.25x = 20.
x=16.