Aptitude - Profit and Loss - Discussion

When I read all the comments, I understood one thing.

Everyone reads the question in a different way.

For all who don't understand.

Let,

A = Cost price.

B = Selling price.

C = b - a = Profit.

When selling price is doubled;

Cost price = a.

Selling price = 2b.

Profit = 2b-a --------> (1).

Given that when selling price is doubled, the profit triples;

Ie profit = (b - a) x 3 = 3b - 3a --------> (2).

Equation (1) and (2) are equal, on equating;

3b - 3a = 2b - a ie b = 2a.

B = 2a means the selling price is twice as that of the cost price, which means the profit is another 'a'. (ie) 100%.

Most of you get confused by this question because you think that we have to find the profit percentage when the selling price is doubled.

But it's not like that.

They have just given a clue to assume how to take profit.

Let's take C. P as x and S. P as why;
We know that profit is S. P - C. P.
Twice the selling price is not equal to thrice the profit.

2y - x = 3(y - x).

Here, when selling price is doubled (2y) , at that time the profit i.e., (2y - x) is equal to thrice normal profit value3 (y - x).

Then simplifying this 2y - x = 3 (y - x), you will get y = 2x.
Hope you will do the remaining.

Hi, l am Bharathi, how comes 3 (y-x) and (2y-x).

Let cp =10 and sp=20.

Know sp doubles = 40.
And profit triples = 3p.

We know that p = sp - cp.

According to question.

3p = sp - cp.

3(40 - 10) = 40 - 30.
30 = 30.

cp = x sp= y profit = sp - cp so profit=y - x -->(1)

sp = 2times and profit= thrice from given data.
So that sp = 2y and (profit) is 3(y-x) from (1) so that,
3(y - x) = 2y - x.

3(y - x) = 2y - x.

Above, 2y is ok, but why (-x)?

When you are doubling the selling price then why the cost is not increased in proportion to the same. How can you keep it fixed? Kindly explain.

And the equation be 2y - 2x instead to 2y - x.

Thank you for the clear explanation @Balaji.

Let C. P is x answer S. P is y and initial profit is 10.

We know that S. P - C. P = Profit.

y - x = 10-> Eq 1.

According to given condition, if S. P Double profit become thrice of initial profit then, new S. P. Is 2y and profit is 30 and cost price is same as above x.

Now, 2y - x = 30 -> Eq 2.

By solving these two equation, we get x = 10 and y = 20.

So profit % = (y - x) /x= (20 - 10) /10 =100% this is a basic approach.