Aptitude - Profit and Loss - Discussion

First of all, in the problem they had given that if selling price doubles, profit will be tribled.

Actually we have the formulae that
profit = selling price - cost price

Let the selling price be y and cost price be x

From formulae above profit= s.p.-c.p.

Profit= y-x___________(1)

From the data given, if selling price doubles, profit will be tribled. so that

From(1), we can write

profit=y-x, here from the data given if y doubles profit will be tribled. so we can write in place of profit we can write y-x

3(y-x) = 2y-x
y=2x
profit from (1)
profit=2x-x
= x

Then we have to calcute profit percentage, so we have formulae for profit percentage
Profit%= (profit/cost price)*100
= (x/x)*100

Profit% =100%.

Let SP= 10 Rs.

If it is doubled den SP =20rs,

So profit will be 10 Rs nothing but 100% profit.

profit per= ((s.p-c.p)/c.p)*100
c.p=x
s.p=2x
profit per = ((2x-x)/x)*100
=100
simple

3(y - x) = (2y - x) In this eqn how you subtract x from 2y?

I can not undestand pls explain.

I am also not able to understand how you substract x from 2y.. please explain... plz

Balaji explained well thank you very much.

Still I m unable to understand this problem please help me out.

3(y - x)=(2y - x)
This step is not clear for me.

Alternate method:

S.P = C.P + PROFIT.............(1)
2*S.P = C.P + 3*PROFIT...........(2)

eq(2) - eq(1)

S.P = 2* PROFIT

SUBST S.P IN (1), WE GET

2* PROFIT = C.P + PROFIT

therefore, PROFIT = C.P

PROFIT % = (PROFIT / C.P) * 100

FINALLY, PROFIT % = 100%

Help. Please give me an another way to solve the problem.

LET C.P= 10
S.P= 20
SO, PROFIT= (20-10)I.E (SP-CP)

ACC TO THE QUES,

IF S.P DOUBLES I.E 2(20) THEN

PROFIT TRIPLES I.E 3(20-10).

SO, PROFIT PERCNT= (PROFIT/CP)*100

= {3(20-10)/10}*100
= 300%.