Question

Find the loss or gain as percent, if the C.P. of $10$ articles, all of the same kind, is equal to S.P. of $8$ articles.

Answer 1

C.P. of $10$ articles = S.P. of $8$ articles $=₹80$ (Suppose)
$\therefore$ C.P. of $1$ article $=\frac{80}{10}=8₹$
And S.P. of $1$ article $=\frac{80}{8}=10₹$
$\therefore$ Gain = S.P. - C.P.
$=(10-8)₹$
$=2₹$
Gain $\%=\frac{\text{Gain}\times 100}{\text{C.P.}}$
$=\frac{2\times 100}{8}$
$=25\%$