Question

In a certain month, Mr. Khan’s call charges were Rs. 124.80. If in addition to the telephone rent to 380, he has to pay a 5 % tax on the total amount, then what is his telephone bill for that month?
(a) Rs. 430.04
(b) Rs. 530.04
(c) Rs. 630.04
(d) None of these

Answer 1

Hint: To solve the given question, we will first find out the total amount by adding the telephone rent and his call charges which are Rs. 380 and Rs. 124.80 respectively. After finding it, we will find 5 % of this amount, and then we will add it to the total amount to get the telephone bill for that month.

Complete step by step answer:
To start with, we will find out what is the total amount Mr. Khan has to pay excluding the taxes. It is given in the question that his call charges are Rs. 124. 80 and the rent of the telephone is Rs. 380. The total amount will be the sum of the call charges and the rent of the telephone. Thus, we have,
Total Amount excluding tax = Telephone Rent + Call Charges
Total Amount excluding tax = Rs. 380 + Rs. 124.80
Total amount excluding tax = Rs. 504.80
Now, it is given in the question that he has to pay additional tax also. This tax comprises 5 % of the total amount. Now, we know that the total calculated is Rs. 504.80. So, the tax will be given by,
Tax = 5 % of the total amount excluding tax
\[\Rightarrow \text{Tax}=\dfrac{5}{100}\times \left( \text{Total Amount excluding tax} \right)\]
\[\Rightarrow \text{Tax}=\dfrac{5}{100}\times Rs.504.80\]
\[\Rightarrow \text{Tax}=\dfrac{Rs.2524}{100}\]
\[\Rightarrow \text{Tax}=Rs.25.24\]
Now, the total amount he has to pay will be the sum of the total amount excluding tax and the tax. Thus, we can say that,
Total Telephone bill = Total amount excluding tax + tax
Total telephone bill = Rs. 504.80 + Rs. 25.24
Total telephone bill = Rs. 530.04
Thus, Mr. Khan will have to pay a total telephone bill of Rs. 530.04 in that month.
Hence, option (b) is the right answer.

Note: The alternate method to approach this question is shown below.
There are two parts in the telephone bill that Mr. Khan has to pay – one is the total amount and the other is the tax i.e. 5 % on the total amount. Thus, we can say that,
Telephone bill = Total Amount + 5 % of total amount
\[\Rightarrow \text{Telephone bill = Total Amount +}\dfrac{5}{100}\times \text{ Total Amount}\]
\[\Rightarrow \text{Telephone bill }=\dfrac{105}{100}\times \text{ Total Amount}\]
\[\Rightarrow \text{Telephone bill }=\dfrac{21}{20}\times \text{ Total Amount}\]
\[\Rightarrow \text{Telephone bill }=\dfrac{21}{20}\left( 360+124.80 \right)\]
\[\Rightarrow \text{Telephone bill }=\dfrac{21}{20}\times 504.80\]
\[\Rightarrow \text{Telephone bill }=Rs.530.04\]