Aptitude - Profit and Loss - Discussion

I believe your all wrong. There are too many assumptions in this problem.

Nothing is mentioned about the cost. Every single one of you are doubling the cost to get the selling price. The question specifically says double the selling price, not double the cost. If you make a table, this is a better visual.

-------> initial ----- new
SP---> 10 ----- 20
CP---> -5 ----- (- 5)
P---> 5 ----- 15

Selling price as you can see is double and profit is tripled. Cost does not change. Profit is tripled.

profit = sp - cp.
3 profit = 2 sp - cp.
profit = cp.
profit % = profit / cp * 100 = cp / cp * 100 = 100%.

Let, profit percentage=x%.
if c.p is 100 Rs then s.p (100+x).
now we get from the conditions,
2(100+x)-100 = 3x.
or,200+2x-100 = 3x.
or,x = 100.

3(y - x) = (2y - x) this equation is wrong given in answer.

The equation must be 3(y-x)=2y.

Here p=s.p-c.p,
3p=2s.p-c.p,
3(s.p-cp)=2s.p-c.p ---->(p=s.p-c.p),
s.p = 2c.p,
p% = s.p-c.p/c.p * 100,
= 2c.p-c.p/c.p *100,
= 100%.

We know,

p%= ( sp - cp ) / cp * 100-----(1)
So we have sp - cp = ( p *cp )/100-------(2)
we are given that profit is tripled and sp is doubled

So we have profit % 3p.
from one replace p by 3p and sp by 2 sp
we arrive at,
3p=(2sp - cp)/cp *100.
so now
(3p*cp )/100 =2sp - cp.
3(p *cp)/100 =2sp -cp.
we can replace p*cp/100 with (sp-cp) -----from (2).
so 3(sp-cp)=2sp - cp.
3sp-3cp=2sp-cp.
sp=2cp -(3).
so now we have from 1.
p%=2cp-cp/cp *100 (replace sp=2cp).
p%=100.

let profit=p.
s.p.=x.
c.p.=y.

Profit=s.p.-c.p.=x-y
Now profit triple and s.p. double means,
3p=2x-y
but p=x-y ,put in equation
3(x-y)=2x-y
x=2y , we got
profit p=x-y,
p=2y-y=y (x=2y).

Now, profit %= (gain*100)/c.p.
profit %=(y*100)/y (gain p=y, c.p.=y).
profit%=100%.

Well done @Balaji.

@All.

For example
SP=100
CP=50
Profit=100-50=50

Now SP1=2(100)
CP=50
Profit1=200-50=150

So in this case, if selling price increased by double sp1=2*sp then profit1=3*profit... it seems final question requires detailed information. Like total extra profit 150-50=100 which is 100% of selling price.

How about doing this question like this?

Let CP be Rs 100,
then by question SP =200,
then profit percent is;
(SP-CP)*100÷CP,
so ( 200-100)*100÷ 100,
=100.

So required answer is 100, hope I am right please suggest me if I am wrong.