Question

The price of a motor bike is RS. 210000. Find its price with 10% reduction.

Answer 1

Hint: To find the price of the motor bike with a reduction of 10%, we have to find the discount rate (DR) which is the product of principal amount (p) and interest rate (r), where principal amount means the original price of the bike and interest rate is the discount percentage. Then, we have to find the price of the motor bike with a 10% reduction by subtracting the discount rate from the principal value.

Complete step by step solution:
We have to find the price of the motor bike with a reduction of 10%. Here, reduction means discount. We know that the discount rate (DR) is given by the product of principal amount (p) and interest rate (r).
$\Rightarrow DR=p\times r$
Principal amount means the original price of the bike. Thus, we can write p as
$p=Rs.210000$
Interest rate is the discount percentage.
$\Rightarrow r=10\%$
Therefore, we can find the discount rate as
$\begin{align}
  & DR=210000\times 10\% \\
 & \Rightarrow DR=210000\times \dfrac{10}{100} \\
 & \Rightarrow DR=Rs.21000 \\
\end{align}$
Now, we have to find the price of the motor bike with 10% reduction. For this, we have to subtract the discount rate from the principal value.
\[\Rightarrow \text{Price of Motor bike = p}-\text{DR}\]
Let us substitute the values in the above formula.
\[\begin{align}
  & \Rightarrow \text{Price of Motor bike =}210000-21000 \\
 & \Rightarrow \text{Price of Motor bike =}Rs.189000 \\
\end{align}\]

Hence, the price of the motor bike with 10% reduction is 189000.

Note: Students must know the formulas related to the discount. They must forget to convert percentage into number by dividing by 100 when finding the discount rate. We can find the discount percentage when marked price and discount rate is given by using the formula
$\text{Discount percentage}=\text{Marked price}\times \text{Discount rate}$
Marked price means the original price or the principal amount.
We can find the discount by subtracting Selling price (price that customer pays) from Marked price.
$\Rightarrow \text{Discount}=\text{Marked price}-\text{Selling price}$