Question

Riyaz bought a TV set marked at Rs. 30000. He got a discount of 10% and paid a sales tax of 7% then how much did Riyaz pay for the TV set?

Answer 1

Hint: We solve this problem by using the simple formulas of commercial mathematics. If the marked price of an object is M.P and have a discount of \[x\%\] then the cost price is given as
\[C.P=M.P-\dfrac{M.P\times x}{100}\]
Also, if there is a cost price of C.P then the final cost price after paying \[y\%\] sales tax is given as
\[T=C.P+\dfrac{C.P\times y}{100}\]
By using the above formulas we find the amount paid by Riyaz.

Complete step by step solution:
We are given that the Marked price of the TV set as 30,000/-
Let us assume that the market price of the TV set as
\[\Rightarrow M.P=30,000\]
We are given that Riyaz got \[10\%\] discount
Let us assume that the cost price of the TV after applying the discount as \['C'\]
We now that, if the marked price of an object is M.P and have a discount of \[x\%\] then the cost price is given as
\[C.P=M.P-\dfrac{M.P\times x}{100}\]
By using the above formula to given problem we get
\[\begin{align}
  & \Rightarrow C=30,000-\dfrac{30,000\times 10}{100} \\
 & \Rightarrow C=30,000-3,000=27,000 \\
\end{align}\]
We are given that Riyaz paid \[7\%\] of sales tax.
We know that if there is cost price of C.P then the final cost price after paying \[y\%\] sales tax is given as
\[T=C.P+\dfrac{C.P\times y}{100}\]
By using the above formula to given problem we get
\[\begin{align}
  & \Rightarrow T=27,000+\dfrac{27,000\times 7}{100} \\
 & \Rightarrow T=27,000+1890 \\
 & \therefore T=28,890 \\
\end{align}\]
Therefore Riyaz pays a total of 28,890/- for the TV set.

Note: Students may make mistakes in applying the sales tax.
We have the formula of price after applying the sales tax as
\[T=C.P+\dfrac{C.P\times y}{100}\]
Here, C.P is the cost price, not the market price.
So applying the formula we get
\[\begin{align}
  & \Rightarrow T=27,000+\dfrac{27,000\times 7}{100} \\
 & \Rightarrow T=27,000+1890 \\
 & \therefore T=28,890 \\
\end{align}\]
But students may take the formula wrong and apply formula as
\[\Rightarrow T=27,000+\dfrac{30,000\times 7}{100}\]
This gives the wrong answer.