A customer using a certain telephone calling plan pays a fee of $25 per month, and then receives a discount of 40% on the regular charge for all calls made to country W. If calls to country W are regularly charged at $1.60 per minute for the first 3 minutes, and $0.80 per minute for each minute thereafter, what is the maximum the customer could have saved over regular prices if he was charged for 1 hour of calls made to country W in a certain month?  Options.
A) $8.75
B) $12
C) $13.40
D) $17.40
E) $24.40
Discount = 40% of spending   We want to maximise discount so we will need to maximise spending. We do that by assuming that 60 calls were made of 1 min each because the first minute is the most expensive.   Max discount = (40/100)* 60 * 1.6 = (40/100)*96   This would be slightly less than 40. About 38 to 39.   Saving = (Slightly less than 40) - 25 = Slightly less than 15 charged in W country   Answer ($13.40)
<result>C</result>
A customer using a certain telephone calling plan pays a fee of $25 per month, and then receives a discount of 40% on the regular charge for all calls made to country W. If calls to country W are regularly charged at $1.60 per minute for the first 3 minutes, and $0.80 per minute for each minute thereafter, what is the maximum the customer could have saved over regular prices if he was charged for 1 hour of calls made to country W in a certain month?