Question

The price of a scooter was Rs.34000 last year. It has increased by 20% this year. What is the price now?

Answer 1

Hint: To solve this question, we will calculate 20% of given price Rs.34000. This can be done by $\dfrac{20}{100}\times 34000$ and then add it to old price.
Also, we can use formula of new price as = old price + 20% of old price.
20% of old price is nothing but 20% of 34000 = $\dfrac{20}{100}\times 34000$

Complete step by step answer:
We are given that, the price of scooter was Rs.34000. This was the price last year.
The price of the same scooter is increased by 20% now.
If the original price of a commodity is x, then if the price is increased by y% then the new price of a commodity can be given by the formula:
Original price = x
New price = $x+\dfrac{x\times y}{100}$
That is, new price is old price added to y% of old price x.
\[\text{New price}=x+\dfrac{xy}{100}\]
Here we have original price = x = Rs.34000 and y = 20%
Then, by applying the above stated formula, the new price becomes.
New price of scooter \[\begin{align}
  & \Rightarrow x+\dfrac{xy}{100} \\
 & \Rightarrow 34000+\dfrac{34000\times 20}{100} \\
\end{align}\]
Cancelling 100 from denominator we have:
\[\begin{align}
  & \Rightarrow 34000+340\times 20 \\
 & \Rightarrow 34000+6800 \\
 & \Rightarrow 40800 \\
\end{align}\]

Therefore, the new price of scooter this year is Rs.40800

Note: The key point to note here in this question is that because the new price is increased by 20% of the old, therefore we have added the old price to the 20% of old price.
But if in case the new price is decreased by some percent then we would have subtracted the 20% or any given percent times old price to the old price, as then we want the new price to be decreased.