Question

When the price of an article is increased by $p\%$ the quantity of sales decrease by $10\%$ but sales revenue increase by $10\%$. Find $p$.

Answer 1

Let the earlier price be $x$ and quantity of sales be $y$

current price = $(1+p)x$ current quantity = $0.9\ast y$

earlier sales revenue = $xy$, current sales revenue = $(1+p)x\ast 0.9y$

Atp,

$(1+p)x\ast 0.9y$ = $1.1\ast xy$

or $(1+p)=\frac{11}{9}$

or$p=\frac{2}{9}$

or $p=\frac{200}{9}\%=22.22\%$