Aptitude - Profit and Loss - Discussion

Thanks for the explanation @Sanjeeth.

Profit = 25%.

%profit= ((sp-cp) /cp)) * 100.
cp = x.
sp = 20.
25 = (20-x / x)*100.
x = 20 * 4-4x.
3x = 80.
x = 16.

25 is the answer.

Cost price 20(1+25%100).
20*125%100 = 25.

CP*20 = SP*X.
CP/SP = X/20.
100/125 = X/20(profit is 25%, therefore if we take CP as 100% then SP will b 125%).
X = 16.

Given:

CP of 20 articles= SP of X articles.
(they said ''Let CP be 1 foe each article'').
For better understanding let be do it with the next number.

Let the CP be 2.

CP fox X articles = 2X.

CP of 20 articles= SP of X articles(given).
2 x 20 = SP for X articles.

Profit= SP - CP.
= 40-2X.

Profit %= Profit x 100/CP.
25 = 40-2X x 100/2X
25 = 20-X x 100/X
X = 20-X x 100/25
X = (20-X) x 4.
X = 80- 4X.
X + 4X = 80.
5X = 80,
X= 16.

Well said, Thanks @Mateen Wani.

Simple method:

Equation is C. P of 20 articles = SP * x.
C. P is always supposed Rs 100,
P=S.P-CP.
25=S.P-100,
S.P=25+100,
S.P=125.

Now
CP=100,
SP=125,
P=25.

Put into equation
C. P * 20 = sp * x,
100 * 20 = 125 * X,
100 * 20/125 = X.
16 = X.

I think answer is incorrect because it said the CP of 20 articles = SP.

S.P = x.

Then CP will be of 20 article = 20x.

Let's say the cost price of 20 articles = 100
the selling price of X articles= 100
Gain=25%.

So the cost price of 1 article = 100/20=5.
The selling price of 1 article = 100/X,
Formula= {100/(100+gain%)} * S.P.
5 = {100/(100+25)} *100/X.
Hence X = 16.

20 * 100/125 = 16.