Question

For her mobile phone service Divya pays Rs.145 per month and 75 paise for each extra minute she talks over the allowed number of minutes in the monthly plan. She received a bill of Rs.178 last month. How many extra minutes did she use her phone beyond the allowed time?
A) $20$
B) $24$
C) $44$
D) $40$

Answer 1

Hint: First, evaluate the amount which is charged on the extra minutes. The total bill amount is the sum of the fixed charge per month and the amount she charged for extra minutes.

Complete step-by-step answer:
We are given that Divya pays Rs. $145$per month for her mobile phone service and $75$ paise for each extra minute she talks over the allowed number of minutes in the monthly plan.
Let the number of extra minutes is $x$.
First, convert $75$ paise into rupees.
We know that $100$ paise is equal to Rs. $1$
Therefore, $75$ paise is equal to Rs. $0.75$.
Now, extra minutes are $x$ and the amount charged on each extra minute is Rs. $0.75$. Therefore, the total extra amount will be the product of the total number of extra minutes and charge of each minute.
That is, $0.75x$
Since, the bill includes the total amount, therefore, Rs. $178$is equal to the sum of Rs. $145$and total extra amount charged.
That is, $0.75x + 145 = 178$
Simplify the equation to evaluate the value of $x$ by taking constants at one side.
$
   \Rightarrow 0.75x = 178 - 145 \\
   \Rightarrow 0.75x = 33 \\
 $
Divide both sides by $0.75$.
$
   \Rightarrow x = \dfrac{{33}}{{0.75}} \\
   \Rightarrow x = 44 \\
 $

$\therefore$, $44$ extra minutes, she used her phone beyond the allowed time. Hence, option (C) is correct.

Note:
We can solve this question directly by option.
The difference in the bill and she pays per month is Rs. $178 - 145 = 33$ and charge for each minute is Rs.$0.75$.
Therefore, that option will be our answer whose product and $0.75$is equal to $33$.
Option-(C)
$44 \times 0.75 = 33$
Hence, option (C) is correct.