BSNL charges a fixed rental of Rs. 350/month. It allows 200 calls free per month. Each call is charged at Rs.1.4 when the number of calls exceeds 200/month and it charges Rs.1.6 when the number of calls exceeds 400/month and so on. A customer made 150 calls in February and 250 calls in March. By how much percent the each call is cheaper in March then each call is February?
Correct Answer: 28%
Explanation:
Charges of 1 call in February = 350 / 150 = 7/3
Charges of 1 call in March = [350 + ( 50 x 1.4) ] / 250
= 420 / 250
= 42 / 25 % Cheapness of a call in march = [(7/3 - 42/25) / 7/3] x 100
= 28%
