Aptitude - Profit and Loss - Discussion

Thank you for the clear explanation @Balaji.

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.

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.

@Tushar Vaibhav.

You explained clearly and It is easy when to compare to others.

Thanks for good explanation. Now I got it.

Apply,
SP = (100 + gain%) * cp/100.

If the cp was 50 and so was 100 for the first condition.

In the second case if the sp is doubled i.e 200 profit becomes three times i.e 150 so it comes 300%.

Can someone tell me where am I going wrong?

P = SP - CP,
As per the question,
3P = 2SP - CP,
3P = SP +SP - CP,
3P = SP + P,
SP = 2P,
P% = 100.

Otherwise,
Sp = P + P,
SP = CP + P,
Hence CP = P,
By formula P% = (P/CP)*100
So, P%=100.

We know that profit = SP - CP.
Let SP - CP = gain
Profit = gain .....(1)

(as per the question when SP is doubled Profit is tripled )
Let increased SP = 2SP
INCREASED PROFIT = 3PROFIT
3PROFIT = 2SP - CP
3PROFIT = SP + SP - CP
From equation (1)
3profit = SP + gain ---> 2.
(1)/(2)

1/3 = gain/(gain + SP ) by inspection .
1/(1 + 2) = gain/(gain + sp).
Hence gain = 1.
SP = 2, hence CP = 1.

Using the formula
profit % = (gain/CP) * 100.
Profit % = 100.

Profit = S.P - C.P.

Profit triples and S.P doubles.

3P = 2 S.P - C.P.
3 (S.P - C.P) = 2S.P - C.P.
So, S.P = 2 C.P.

Gain% = (S.P - C.P) * 100/C.P.
= ( 2 C.P - C.P) * 100/C.P.
= 100%.