Question

if the cost price of 9 pens is equal to the selling price of 11pens then what is gain or loss percentage​

Answer 1

Answer:

11.18%

Step-by-step explanation:

Cp 9 pens=x

Sp 11 pens=2pens(difference of pens 11-9)

Cross multiply

X=1.64 (1 pen cost)

1.64×11=14.27

14.27-1.64

=13.08

13.08/14.727×100= 11.18%

Answer 2

Let cost price of one pen be ‘x’
Then total cost = 9x
Similarly, let the selling price per pen be ‘y’ Then total sales = 11y

To calculate gain/loss percentage ,
We need to know gain/loss which is nothing but Sales - Cost

Hence ( y - x) is our gain.

And further to calculate gain or loss percentage :

(y-x)/x

Given that : 9x = 11y
Which means y = 9x/11

Thereby % =

{ (9x/11 - x) } / x

= -2/11

Since the value of gain is negative which means we have incurred loss of 2/11 x 100
= 18.18%
.
.
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