Question

The cost of telephone calls in an industrial town is 30 paise per call for the first 100 calls, 25 paise per call for the next 100 calls, and 20 paise per call for calls exceeding 200. How many calls can one make for rs.50?

Answer 1

The total number of calls for Rs. 50 will be 180.

Explanation

The cost of telephone calls is 30 paise per call for the first 100 calls.

So, the total cost for first 100 calls $=(30*100)=3000$ paise = Rs. 30

The cost for the next 100 calls is 25 paise per call.

Suppose, the number of calls after the first 100 calls is  $x$

So, the total cost for this $x$ calls $=25x$ paise $=0.25x$ rupees.

Total amount of cost is given as Rs. 50 . So the equation will be........

$30+0.25x=50\\ \\ 0.25x=20\\ \\ x=\frac{20}{0.25}=80$

So, the total number of calls for Rs. 50 will be: $100+80= 180$