Question

In the year $2001$, the price of article $A$ is $20\%$ more than the price of article $B$. In the year $2002$, the price of article $A$ is $50\%$ more than the price of article $B$. From $2001$ to $2002$, if the price of $A$ has increased by $50\%$, by what percent has the price of $B$ increased?

Answer 1

In 2001 year

Let the price of B be $x$

Theb the price of A will be $(x+\frac{20}{100}\times x)=1.2x$

In 2002 year

Let the price of B be $y$

Then the price of A will be $(y+y\times \frac{50}{100})=1.5y$

According to question

$1.5y=1.2x(1+0.5)\Rightarrow 1.5y=1.2x+.6x\Rightarrow 1.5y=1.8x$

For article B

$\Rightarrow y=\frac{6}{5}xy=1.2x=(1+0.2)x$

The price of B increased by 20% from 2001 to 2002 year.