Question

the CP of 21 articles is equal to SP of 18 articles find the gain or loss percentage​

Answer 1

Answer: Gain percentage = 16.67 %

Step-by-step explanation:

Since more articles were bought using the same amount of money gained from selling a lesser number of articles,

C.P < S.P

This shows that it was a gain.

Gain = S.P - C.P

Let C.P be x

Then,

S.P = 21x/18

Gain = 21x/18 - x

       = (21x-18x)/18                         (by taking LCM)

       = 3x/18

Gain percentage = 100 x Gain/C.P %

                            = 100 x (3x/18)/x %

                            = 100 x 3x/18x %

                            = 100 x 1/6 %           (x and x get cancelled and 3/18 = 1/6)

                            = 100/6 %

                            = 16.67 %       (actually a recurring decimal which is 16.666... but I have rounded it up to 16.67. When writing on paper you can write it as 16.6 and put a dash on top of the 6 after the decimal.)