Question

Rs. 25000 becomes Rs. 31000 in four years if the interest is simple. If the rate of interest is increased by 4% then what will be the total amount after two years?

Answer 1

Hint: For solving this question you should know about the rate of interest. In this problem we have asked for two total amounts and we will find the first rate by the given amounts and then we increase that rate by 4% and now we again calculate a new amount for this new rate.

Complete step by step answer:
According to our question it is asked to find the total amount after two years if the rate of interest is increased by 4% and first the Rs.25000 becomes Rs. 31000 in four years if the interest is simple.
So, we can understand here that we have given two amounts first. We will calculate the interest rate for that amount and then we will calculate a new amount if the rate of interest is increased by 4%.
So, the simplest interest for 4 years given \[=3100-2500=600\]
Then the rate of interest \[=\dfrac{S.I.\times 100}{PT}\]
\[\begin{align}
  & \Rightarrow R=\dfrac{600\times 100}{2500\times 4} \\
 & \Rightarrow R=6\% \\
\end{align}\]
After increase of 4% the new rate of interest \[=10\%\]
S.I. at this rate of two years \[=\dfrac{2500\times 10\times 2}{100}=500\]
Therefore, Amount = Principal + Simple interest
Amount \[=2500+500=3000\]
So, the amount is 3000.

Note: While solving these type questions you should know about the simple interesting very good way. Because most of the questions change their time and rate and always asks for the amount or if they change anything different in that but we can calculate all these by that formula.